Isaac Roberdeau (1763-1829) Civil Engineer and Surveyor

Among the notable early American surveyors and engineers must be included Isaac Roberdeau (1763-1829), who began his professional career on the first survey of the Federal Territory, to establish a national capital which became Washington, D. C. The eldest son of Daniel Roberdeau—a wealthy French American, congressman, and a Revolutionary War general—and his wife Mary Bostwick, Roberdeau grew up in Philadelphia where he was born. He was educated locally, and in 1783 was employed as one of four clerks serving under Joseph Nourse, registrar of the Treasury Department.


Assistant to L'Enfant
In the same year young Roberdeau visited the West Indies with his father, before embarking for London where he studied engineering. While in England he inspected the great canals. He returned to Philadelphia in 1787 and it was only a few years before he became engaged in public service. While Pierre Charles L'Enfant was assembling a topographical force for laying out the city of Washington, young Roberdeau's French ancestry coupled with his technical training brought him to L'Enfant's notice. In 1791, at the instance of General Washington, L'Enfant employed him on his staff as assistant engineer during 1791 and 1792.

Roberdeau was gaining some valuable experience in the course of the work, but through no fault of his own, he became involved with the difficulties resulting from a conflict between L'Enfant's views with those of the commissioners of the District. Under L'Enfant's direction, Roberdeau had been put in charge of a party of workmen who destroyed the masonry of the uncompleted house of Daniel Carroll of Duddington. L'Enfant had ordered the demolition on the grounds that the house's erection contravened the agreement made between the Federal government and the original proprietors of the land. This was the principal cause that led to the dismissal of L'Enfant by General Washington. Then, in January 1792 Roberdeau gained more unwelcome notoriety when he was arrested by the commissioners for refusing to stop digging the foundations for the Capitol after they had formally dismissed him.

After L'Enfant had been dismissed by President Washington, he went to Paterson, New Jersey, where Alexander Hamilton had planned to create the ideal American industrial city on the Passaic River. Roberdeau followed L'Enfant to New Jersey, but after finding that there was no position there for him, he returned to Philadelphia. There, on November 7, 1792, he was married to the granddaughter of Samuel Blair and William Shippen, and in time they were the parents of three daughters. Immediately after marriage he took up the practice of civil engineering in his home state of Pennsylvania, a profession in which he remained engaged during the next two decades.

For the next several years, beginning in 1792, Roberdeau was involved in surveying canals in Pennsylvania, Delaware, and New Jersey. His major work was in the scheme directed by the English engineer, William Weston, to build a canal that would connect the Schuylkill and the Susquehanna Rivers. The project had been first proposed by William Penn in about 1690, a project that was not to be completed until many years later. With Roberdeau's involvement the canal proceeded about fifteen miles before it had to be abandoned for lack of funds. The route was later surveyed by David Rittenhouse and Dr. William Smith. It was not until 1828, however, that the Union Canal Company completed this project, the year before Roberdeau's death.

In 1798 Roberdeau unsuccessfully applied for the position of superintendent of a proposed national cannon foundry, citing not his direct experience but his wide knowledge of people involved in the field. Two years later he submitted an application to the War Department for the position of purveyor of public supplies. On February 22, 1800, while directing a brigade that was building a canal near Trenton, Roberdeau—who had dined at Mount Vernon in 1783—had the occasion to deliver "An Oration Upon the Death of General Washington," which was published in the same year.

Roberdeau's ambition had long been for service in the army, but it was not until about ten months after the beginning of the War of 1812 that finally he managed to obtain an appointment, in the newly established Corps of Topographical Engineers of the United States Army. The highest rank authorized for the Corps was that of major, and on April 29, 1813, Roberdeau was among the first four to be appointed to that rank. He was assigned to duty at Fort Mifflin near Philadelphia, and was engaged in fortification work on various locations, until his unforeseen discharge. This was caused by a Congressional oversight, that inadvertently disestablished the Corps on June 15, 1815.

Civilians on Active Duty
The War Department was not inclined to dispense with the topographical engineers, however, and pending legislation, Roberdeau and another engineer named John Anderson were "provisionally retained" as civilians on active duty on the survey they had begun of the northern frontier. From June until December 1815 the two men led the team that surveyed that part of the boundary between the United States and Canada lying between Whitehall, New York, the headwaters of Lake Champlain, and Niagara Falls. The boundary was set in the middle of the waterways by the Treaty of Ghent. Roberdeau and Anderson also examined the fort at Crown Point, New York, and reported on its condition, recounted its history, and made recommendations for its repair.

After the Corps of Topographical Engineers was re-established, Roberdeau was fully reinstated to his former rank in May 1816, and stationed at West Point, the headquarters of his Corps. In May 1818 he joined the commissioners appointed to examine Hampton Roads near Old Fort Comfort, and in July he was ordered to undertake a survey of Annapolis. On August 1, 1818 the Topographical Bureau, with Roberdeau as its head, was transferred permanently to Washington, D. C.

By 1819 Roberdeau had become involved with the seacoast survey which originally had been proposed by Thomas Jefferson in 1807, and that had been launched officially in 1816. In 1820 Roberdeau was given the responsibility for the care of the costly instruments that had been ordered from Europe for the U. S. Coast and Geodetic Survey by Ferdinand Rudolph Hassler, first Superintendent of the U. S. Coast and Geodetic Survey.

After John C. Calhoun was appointed Secretary of War in 1820, Roberdeau was selected to accompany the Secretary on many of his tours of inspection; in May 1820 Calhoun ordered that Roberdeau be awarded five months of extra pay retroactively for preserving the War Department's maps, plans, and mathematical instruments. Thereafter Roberdeau was placed in permanent charge of maintenance of the government's surveying and weighing instruments.

In 1821, using borrowed Hassler instruments, Roberdeau assisted the astronomer William Lambert in making observations for calculating the longitude and latitude of the Capitol in Washington.

Prominent in Washington Society
In 1823 Roberdeau, now at the age of sixty, was given the brevet rank as lieutenant colonel. He spent the remainder of his life in the national capital, where he became a prominent figure in Washington society, entertaining many notable guests at his home in Georgetown, among them the Marquis de Lafayette during the latter's visit to the United States. Roberdeau was a handsome man, described as "tall and of a distinguished military bearing, resembling the Duke of Wellington so strongly that he was mistaken for him while traveling in England." He died at his home in Georgetown on January 15, 1829 at the age of sixty-three.

Roberdeau was the author of several important works in his field, including Observations on the Survey of the Seacoast of the United States, which he read before the Columbian Institute in Washington in December 1826, and which was published in the following year. He was unsuccessful in 1828, however, in obtaining support to publish his substantially illustrated essay on canal design, titled Mathematics and Treatise on Canals.

Roberdeau was adamant in his view that the coast survey should be undertaken by the Topographical Corps of Engineers, and that a national observatory in Washington was essential to ensure the accuracy of the survey, a project he discussed frequently, among others also with his friend, President John Quincy Adams. On November 19, 1825 the President noted in his diary a visit from "Roberdeau, Colonel, came at eleven. I walked with him to W. Elliot's on Capitol Hill, where with a small transit instrument they observed the passage of the sun over the meridian. Conversation about the erection of an observatory."

This encounter appears to have marked the initiation of a crusade undertaken by President Adams for the erection of a national observatory. [For further details concerning the support for a national observatory by President Adams, see The Jefferson Stone. Demarcation of the First Meridian of the United States by Silvio A. Bedini, published by Professional Surveyors Publishing Company, 1999), pp. 50-53.]


About the Author

  • Silvio A. Bedini
    Silvio A. Bedini
    Silvio A. Bedini was a Smithsonian Institution historian who specialized in the history of scientific instruments and mathematical practitioners. A former deputy of the National Museum of American History, he has authored over 20 books and was Historian Emeritus with the Smithsonian Institution in Washington, DC. He was also a contributing author at the magazine for many years.

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