04 - Principio Furnace

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The Principio Furnace, Maryland's first iron worksd, was established in 1719 in Cecil County and consumed 10,000 acres of woodland during its 100 years of operation.

Text By Milt Diggins - Cecil County Historical Society

Principio Iron Works Office
Photo by Hank McComas

Until recently, people driving past the site of the old Principio Iron Works and looking beyond the distinctive former office building would have observed a tract obscured by a thick growth of trees, bushes, and weeds; the imposing obstacles reinforced by "No Trespassing" signs. The French Second Empire designed office building and a state historic site plaque offered the only clues of the historic significance of the Principio area, and its industrial vitality. Within the last few years the site has been transformed.

Stand at the fence behind the office, look across the field, and you will observe a round charcoal kiln and the remains of a wash house. Scan to the left and you will notice a two-story building that housed machinery and, in the foreground of that building, traces of foundations. Walk east along the fence, and visually search near the creek, not as far back as the two-story building, and you might notice the 1837 blast furnace. In the Summer and early Fall the view is partly screened by trees.

Stand at the corner of the fence, and survey along the bottom of the hill and you will spot the brick remains of the blacksmith and wheelwright shops, the wooden wagon barn, and the path of the mill race. Look over the east fence, and you see a corn crib and the remaining walls of a barn. On the opposite side of Principio Furnace Road are buildings associated with the former manufacturing complex, the most notable being the ironmaster's mansion on the hill, a short distance northwest of the old office building. "No Trespassing" signs are still visible on the Principio property, but now a phone number offers an invitation for those who wish to visit the site.

      Activity from a variety of people is reawakening Principio Iron Works - owners, caretakers, contractors, archaeologists, government employees and officials, student groups, and visitors are revitalizing the site. In April, 1981, York Building Products, a subsidiary of Steward and March, purchased the land from the Whitaker Iron Company, and Robert Steward, founder of Steward and March, is considering a number of options for preserving historical integrity, promoting historic significance, and increasing public access of the site.


Colonial Maryland's economy was heavily dependent on agriculture, with only one significant manufacturing industry, iron production. When Maryland settlers established the colony in 1634, most investors were buying land for tobacco plantations, the presence of iron ore attracted little attention. It was not until around 1715 that Maryland had its first ironworks, a small bloomery operation, located near North East and owned by Robert Dutton. A bloomery produced wrought iron, or bar iron, by the iron worker heating iron ore in a hearth and hammering the molten iron to remove slag, the impurities in the iron ore, and then shaping the metal into blooms or bars. Using this one-step method, a bloomery could produce around one hundred pounds of iron a day. A higher rate of production and higher quality iron would require a two-step process involving the use of a blast furnace and refinery forge (Institute 4, Robbins 6-7). For more detail on iron production, see the separate feature on colonial iron making.

Around the same time blooms were being manufactured in North East, the Maryland General Assembly was recognizing the economic advantages of using iron resources located in the colony. In 1719, the Maryland Assembly approved "An Act for the Encouragement of an Iron Industry." Owners of uncultivated land near streams who committed to building a forging mill within four years were granted an additional one hundred acres of land, on the condition that pig iron was produced within seven years. Up to eighty mill workers were to be levy free (not required to provide labor for a public works project like working on roads, or military service). In 1721, the exemption from the yearly levy to work on roads was extended to furnace and forge workers.

Influenced by the Maryland act and seeing the potential for profits by furnishing iron for British industry, a group of investors in London formed the Principio Company as a joint stock company on March 4, 1720. The original investors were Joshua Gee, Joseph Farmer, William Russell, Thomas Russell, John Ruston, and Stephen Onion. Ironmaster John England joined the partnership two weeks later, and would have a key role in the successful construction of Principio Iron Works. Ownership in the company was not static, new partners would join, and heirs would replace original members. By 1729, one of the partners was Augustine Washington, father of George Washington. When Augustine died, his share in the company passed on to his son Lawrence (Institute 8-9).

Prior to official formation of the company, Joseph Farmer traveled to America and inspected potential sites in the area. When he inspected Back Creek, west of the town of North East, he judged it to be a favorable site for the ironworks. Back Creek dropped at the fall line, building sufficient speed for turning a waterwheel. Beside the stream, the flood plain was wide enough to accommodate a furnace and buildings. The mouth of Back Creek widened into the Chesapeake Bay, providing a harbor in an era when navigable waterways provided the cheapest and easiest means of transportation. Not only could processed iron be shipped out, but oyster shells for lime, and additional iron ore could be shipped in. There appeared to be an abundance of timber for making charcoal, and sufficient iron ore deposits for making iron. The Principio Company renamed Back Creek as Principio Creek; in Latin, Principio means first or beginning (Institute 8).

The Company sent Stephen Onion to America to establish the ironworks. Stephen Onion proved to be more interested in pursuing his own business opportunities, and the work at Principio languished. Ironmaster John England arrived next. Appalled by the lack of progress at the site, he immediately moved to correct the situation. John England supervised construction of Maryland's first blast furnace and first refinery forge; in 1725, the furnace was producing pig iron, and in 1728, the forge workers were hammering out wrought iron. The research literature about the forge is sometimes confusing, jumping between references to one forge and two forges; there were two refinery buildings, usually identified as a single forge (Institute 9-11).

Management of Principio property was similar to the plantation model. Iron was produced for export, and food was grown to provide a measure of self-sufficiency. A company store sold merchandise to workers, although others not associated with the company could make purchases. Slaves and indentured servants were the major sources of unskilled labor. Initial resistance to the idea of training slaves to become skilled labor, was overcame by the company's practical need for more skilled workers; some slaves held skilled positions at Principio (Robbins 45,110-111). Skilled workers were needed for the foundry and forge work, and the clerical tasks. The number of workers used at the site is unknown, but the iron works may have employed as many as the Hopewell Furnace in Pennsylvania - 250 workers. Various tasks required large numbers of workers. Large groups were needed to dump layers of iron ore, charcoal, and oyster shells into the furnace, cut wood and assist in the production of charcoal, and haul wagon loads of raw materials and processed iron (Institute 11).

Most of the pig and bar iron manufactured in the colonies was exported to England, where it would be made into more profitable finished goods; Britain did not permit the colonies to compete in production of finished goods, one of the economic grievances expressed by the colonists before the Revolution. Determining the amount of iron shipped to Britain by the Principio Company is difficult because the British officials combined Maryland and Virginia statistics. "Production of iron which was shipped to England from Maryland and Virginia in 1736 was 2,458 tons of pig iron or nearly ninety per cent of the total shipped to the mother country from the colonies. While it is not known what percentage of the total came from Principio Company enterprises, it is known that both company furnaces [Principio and Accokeek] were capable of producing twenty tons of pig iron per week each . As much as one-third of the year's total" (Robbins 55-56).


 Right after the American Revolution, iron production decreased in the United States. However, Principio had experienced several decades of decline even before the Revolution began. Originally, The Principio Company over-estimated the amount of iron ore available in the immediate area, and this quickly became apparent to John England when he arrived to oversee the operation of the ironworks (Robbins 27). Even before the ironworks complex was in full production, the company purchased land at other locations to increase the supply of iron ore. One site, Accokeek, located in Stafford County, Virginia, was acquired in 1725, on land owned by Augustine Washington. In an agreement with Washington, ore was mined on his land and processed in a blast furnace constructed at that site. The iron was then sent to Principio for refinement in the forge. In 1727, a site was purchased at Whetstone Point, near Baltimore harbor. Iron ore from Whetstone and pig iron from Accokeek were shipped up the Chesapeake Bay by company sloops to a landing near the mouth of Principio Creek. In 1735, the Principio Company established a refining forge at North East to expand processing capacity (Institute 11-12).

By the 1750's, the growing supply of iron from colonial ironmakers drove the price of pig iron and bar iron downward. Shipping ore to Principio for pig iron production became relatively expensive. The Principio Company acquired two blast furnaces in Baltimore County, building one in 1744 and purchasing the other one in 1751, to reduce the distance between the company's blast furnaces and its Patapsco iron ore deposits, increasing profitability for the Company. Shipping pig iron from the distant Accokeek site to Principio for forging became less practical and the Virginia site ceased operation around 1755 (Institute 11-12).

Decline became visible at Principio. In 1749, a visitor reported that "the furnace and buildings were in a very poor condition"(Institute, 13). Existing company records indicate the blast furnace at Principio ceased operation around 1753 (Robbins 63-65). The refinery forge remained active for a while longer, refining pig iron shipped from the Stafford County furnace before that furnace was shut down around 1755, and then continuing to refine iron from the two more profitable Baltimore County furnaces. The Principio Forge deteriorated, and in spite of repairs in 1772, it was no longer in operation by 1776. A shrinking profit margin was not the only factor in Principio's demise. Although the company owned approximately 12,000 acres of timberland by 1725, failure to replant trees contributed to timber depletion close to the furnace. Additionally, the persistent labor shortage problem was aggravated by the outbreak of war (Institute 11-13).

Maryland ironworks supported the colonial war effort. There is a popular belief that Principio supplied the Continental Army with ordinance during the Revolution, but there is no supporting evidence for that view, and it may have originated from confusing the Principio Company with the Principio site. The Principio Furnace was shut down in the early 1750's, and the Principio Forge went out of operation shortly after the outbreak of the War. The Principio Company may have supplied iron to the colonial forces during the Revolution, but most likely only from its remaining Baltimore County furnaces. Documentation indicates colonial ammunition was manufactured at the Principio Company's Kingsbury Furnace, and the ironmaster there actively supported the rebellion (Robbins 282-283).


The Principio Company was incorporated as a British company, and with the American Revolution nearly over, the Maryland government seized control of Principio property in 1781 and auctioned it off several years later. Under ownership of Colonel Samuel Hughes and associates, either the old furnace was rebuilt or a new one constructed and named Cecil Furnace. By 1801, Hughes was the sole owner of the property. Hughes was experienced in the production of cannons and related ordinance, and military ordinance became the primary product manufactured at Principio (Robbins 288-9). The complex included a foundry for molding and casting, and a boring mill to bore five cannons simultaneously. Among the government contracts Hughes received was an order in 1796 to manufacture cannons for the U. S. Navy's first warships, the frigates Constitution, Constellation, and United States. The request was for twenty-four nine-pounders, twelve six-pounders, and forty twelve-pounders (Robbins, 288).

During the War of 1812, the British fleet, projecting its military power along the shores of the Chesapeake, targeted the cannon production at Principio. The British destroyed the complex in a raid in May 1813 (Institute 14-5). The destruction included sixty-eight cannons. (Hickey 153). Hughes unsuccessfully attempted to rebuild, fell deeply into debt, and lost the property to creditors.


Principio experienced another revival when purchased by the Whitaker Family in the 1830's. The Whitakers were experienced ironmasters and owned several iron making operations besides Principio. Joseph Whitaker I began the legacy, working at Hopewell Furnace in 1781. In 1921, the Whitaker family, owning several iron and steel companies, took a major role in the founding of the Wheeling Steel Corporation, which later became the Wheeling-Pittsburgh Steel Corporation in 1968 (Institute 15, May 210-11). In spite of a number of factual errors, especially sections containing "manufactured" dialogue (Institute 55, Whitaker), May's book, Principio to Wheeling, gives a detailed accounting of the various business interests of the Whitakers. The Whitaker involvement in the iron and steel industry lasted over two hundred years, ending with the recent retirement of George Whitaker from Pittsburgh Steel (Whitaker).

In 1836, the sons of Joseph Whitaker, George Price Whitaker and Joseph Whitaker II, along with Thomas Garrett, and William Chandler, purchased the Principio property and established the Principio Iron Works. Buildings were in a state of ruin, but the site still had important advantages. Principio Creek remained an attractive source of waterpower. Crossing the property was a new feature, the track of the Philadelphia, Wilmington, and Baltimore Railroad. With America's industrial growth, the railroad would prove to be an indispensable means of transportation for manufacturers gathering raw materials from distant locations and shipping finished products to larger markets. (Institute 15-17)

The brothers restored the property for iron production. In 1837, A new blast furnace was in operation. Water flowing through a mill race powered the machinery that created the cold blast of air that would intensify the furnace heat. By 1856, a hot last system replaced the cold blast. The hot blast system heated the incoming air, producing a more efficient burning of the charcoal. New tree growth on Principio timberlands provided a steady supply of charcoal (Institute 16-17).

George Price and Joseph Whitaker anticipated the Civil War, and considered the business repercussions of a possible break-up of the United States along the Mason-Dixon Line. They dissolved the partnership, and divided the assets geographically. Joseph took the Pennsylvania properties and George Price kept the Maryland and Virginia properties. George Price Whitaker maintained control at Principio, and managed the operation. He could survey the operation of the iron works from the ironmaster's mansion on a small hill opposite the company office building (institute 16).

The American Civil War increased the need for a variety of iron products, and the iron industry grew during this period. Whitaker took advantage of this period of prosperity, and made improvements to the Principio complex. In 1866, workers constructed a dam on Principio Creek. A new conduit directed water from the dam to the mill race. A water turbine was installed to operate the blast machinery, and other machinery. The horizontal blowing engine and the hot blast furnace may have been put in place around this same time period. To improve output, stone masons increased the height of the furnace by three feet, bringing it to 35 feet (Institute 17-18).

A later phase of expansion began in the 1880's. A forge containing twelve hearths was constructed. The forge could process more than the eight tons of pig iron the blast furnace could produce in a day. A second blast furnace was erected to boost daily production, and was operating by August 1890. It was a cupola-style metal clad hot blast furnace that used charcoal for heating the iron ore. The blowing engine for the blast was located in a brick two-story building. The new blast furnace did not require a hill or ramp to enable workers to dump raw materials into the furnace; a steam-powered hoist lifted these materials to the mouth of the furnace. A brick charcoal kiln was designed with adjustable openings around the sides of the building so workers could control air flow and the rate of burning. Near the kiln were charcoal barns for cooling and storing charcoal, a scale house for weighing charcoal yields, and a workers' wash house for cleaning-up. The new blast furnace and related structures were in place, Principio was readied to increase production, and then suddenly most of the new facilities ceased operation. December 1890, George P. Whitaker died (Institute 18-19). His death marked the end of expansion, and the beginning of contraction of industrial activity at Principio.

Nelson E. Whitaker managed the Principio Forge Company, incorporated by Wheeling investors just prior to George Price's death. Company emphasis was placed on forging charcoal blooms by using pig iron purchased from other producers, and scrap metal that came primarily from the Whitaker's Wheeling plant. After a half year of operation, new blast furnace was permanently shut down. The 1890 blast furnace was dismantled and removed around 1908, and additional metal associated with the furnace was cleared from the area by 1917, but the 1837 furnace was intentionally preserved (Singewald 166, Institute 21). The 1837 blast furnace was used occasionally before shutting down for the last time in 1894. In 1891, the company became the Principio Furnace and Rolling Mill Company, although the proposed rolling mill was not built (Institute 19-21).

William P. Tyler, Nelson E. Whitaker's son-in-law, and the President of the Tyler Tube and Pipe Company, manufactured boiler tubes, and the U. S. Navy was a major customer. Initially, Principio Forge supplied the charcoal blooms used for manufacture of the boilers. Tyler Tube and Pipe Company then leased and directly operated Principio Forge from 1900 to 1925. Demand for wrought iron dropped with the advent of stainless steel. In 1925, a legacy of iron production spanning two hundred years at Principio came to an end (Institute 20). The Whitaker Iron Company, headquartered in Wheeling West Virginia and interconnected with the Wheeling Steel Corporation and other iron and steel industries of that area elected to concentrate its business in the Wheeling area (Whitaker). Abandoned, the forge buildings burned down in January 1942. The weekly Cecil Whig reported the covered the story in three paragraphs.

The site was subsequently used for agriculture. The Principio Christmas Tree Farm operated near the main site from 1956-1993. The main site behind the office became overgrown with vegetation, with only a historical marker and the abandoned office hinting at the former industrial vitality of the site.

Works Cited

Institute for the History of Technology and Industrial Archaeology. Principio Furnace Research and ManagementPlan. Maryland Historical Trust. Crownsville, Maryland, 1998.

Hickey, Donald R., The War of 1812: A Forgotten Conflict. Urbana and Chicago: University of Illinois Press. 1989.

May, Earl Chapin. Principio to Wheeling: A Pageant of Iron and Steel. New York: Harper & Brothers, 1945.

Robbins, Michael. The Principio Company: Iron-Making in Colonial Maryland 1720-1781. Diss. George Washington U. 1972. New York: Garland Publishing Company, 1986.

Singewald, Joseph T., "Iron Ores of Maryland, With an Account of the Iron Industry," Maryland Geological Survey, Vol. IX, Pt. 3. Baltimore: The Johns Hopkins Press, 1911.

Whitaker, Louis, and George Whitaker. Personal Interview. July 28, 2000.


During the American colonial period, Principio was a leading iron producer. Principio held Maryland's first blast furnace, operating in 1725, and first refinery forge, constructed in 1728. One of the company's notable partners was Augustine Washington, father of George Washington. In the early Federal period, Principio manufactured cannons and other ordinance until the British destroyed the complex in a raid during the War of 1812. The Whitaker family took control of the site in 1837, and revived Principio as an active iron manufacturing site for much of the nineteenth century.

Principio is also significant for the following extant cultural resources:

The 1837 charcoal iron furnace together with what was at the time a state-of-the-art hot blast stove, both still have a high degree of integrity Water-powered turbine and blowing engine, the only known example that is still in place Brick beehive charcoal kiln, one of only two of this type still intact in the United States The two story company office, built around 1877-1880, provides an example of the French Second Empire style of architecture Other surviving structures at or near the site, which contribute to the overall integrity of the site Potential archaeological dig sites, especially the sections that relate to the colonial period. "A careful study of the literature, maps, and the Principio Creek below the falls reveals a number of potential furnace and forge locations" (Institute, 22).

The One Step Process

      A bloomery produced wrought iron, or bar iron. The ironworker heated iron ore in a hearth and hammered the clump of molten iron to remove slag, the impurities in the iron ore, and then shaped the metal into blooms or bars. Using this one-step method, a bloomery could produce around one hundred pounds of iron a day.

The Two Step Process

      The indirect or two-step process was more expensive to set-up, but yielded a higher daily rate of production and better quality iron. With this process, iron ore was heated for a sustained period of time in a blast furnace, causing a separation of the iron and impurities. A flux, usually lime, was used to aid in the congealing of impurities, making the separation easier. Charcoal provided the source of heat. Water-power was often used to operate large bellows that pumped air into the base of the blast furnace to intensify the heat of the fire. At the top of the blast furnace, workers added iron ore, charcoal, and flux (oyster shells were the usual source of lime in the Chesapeake region). The furnace was usually around thirty feet high, and a hill or a ramp on at least one side of a furnace gave workers access to the top. Periodically workers would add new layers of these materials. If a sufficient amount of resources were gathered in advance, a charge or blast could burn continuously for several months. The blast operators removed accumulations of slag by opening a tap. From a lower level tap at the base, iron was drained from the furnace several times during a twenty-four hour period.

Then, the resulting pig iron is refined in a refinery forge. The pig iron would be reheated and hammered a number of times to make the iron more malleable, and then the iron was usually formed into bars that could be reshaped into iron products (Robins, 6-9).




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