ELLICOTT, Andrew, civil engineer, born in Bucks County, Pennsylvania, 24 January 1754; died in West Point, New York, 29 August 1820. His father and uncle, who were Quakers, purchased a large tract of wild land on the Patapsco River in 1770, and in 1774 founded the town of Ellicott's Mills, now Ellicott City, where Andrew passed his youth in the study of science and practical mechanics. His scientific attainments soon attracted attention, and he enjoyed the friendship and confidence of Washington, Franklin, and Rittenhouse. He was appointed commissioner at various times for marking the boundaries of Virginia, Pennsylvania, and New York, and about 1785 removed to Baltimore, where he was elected to the legislature. He was selected by Washington in 1789 to survey the land lying between Pennsylvania and Lake Erie, and during that year he made the first accurate measurement of the Niagara River from lake to lake, with the height of the falls and the descent of the rapids.

In 1790 he was employed by the government to survey and lay out the City of Washington, and in 1792 was made surveyor general of the United States. He superintended the construction of Fort Erie, at Presque Isle, now Erie. Pennsylvania, in 1795, and was employed in laying out the towns of Erie, Warren, and Franklin. Washington appointed him in 1796 as U. S. commissioner under the treaty of San Lorenzo el Real, to determine the boundary separating the United States from the Spanish possessions on the south. The results of this service, which embraced a period of nearly five years, appear in his '" Journal" (Philadelphia, 1803). Upon its completion he was appointed by Governor McKean, of Pennsylvania, secretary of the state hind office, but resigned in 1808, and in 1812 became professor of mathematics at West Point, where he remained till his death.

He went to Montreal in 1817, by order of the government, to make astronomical observations for carrying into effect some of the articles of the treaty of Ghent. He was an active member of the American philosophical society, contributed to its transactions, and corresponded with many of the learned societies of Europe. With the exception of his "Journal" and a few other writings, his works are still in manuscript.

His brother, Joseph Ellicott, engineer, born in Bucks County, Pennsylvania, 1 November 1760; died in Batavia, New York, 19 August 1826, received a common school education, and subsequently studied surveying and engineering, He was engaged as all assistant to his brother Andrew in the survey and plotting of the City of Washington, and in running the boundary line between New York and Pennsylvania. In 1797 Mr. Ellicott was employed by the Holland hind company to survey the tract in western New York known as the "Holland purchase," and, on the completion of the survey in 1800, was appointed local agent of the company, with headquarters at Batavia, New York, which he had located, and toward whose early development he contributed largely.

The company among the first to recognize the possibility of building a great City at the foot of Lake Erie on the lands owned Mr. Ellicott that he represented. His influence was largely used not only in promoting settlements in the vicinity of the present City of Buffalo, but also in assisting in its growth and development. Mr. Ellicott has justly been called the "founder of Buffalo." He surveyed and laid out the City on its original plan. He was a zealous advocate of the projected Erie Canal, and corresponded with Governor De Witt Clinton concerning the project. He opposed Clinton's plan of sending to England for engineers, insisting that there was abundant home talent for the work, and succeeded in convincing the governor that he was right. He served for some time as canal commissioner, but held no other public office. After serving the Holland land company twenty years, during which time most of the vast tract of land owned by it in western New York was disposed of to actual settlers, Mr. Ellicott retired from active pursuits.