Civil engineer; born in
Bucks county, Pa., Jan. 24, 1754.
His father and uncle founded the town of
Ellicott's Mills (now
Ellicott City),
Md., in 1790.
Andrew was much engaged in public surveying for many years after settling in
Baltimore in 1785.
In 1789 he made the first accurate measurement of
Niagara River from lake to lake, and in 1790 he was employed by the United States government in laying out the city of
Washington.
In 1792 he was made surveyor-general of the
United States, and in 1796 he was a commissioner to determine the southern boundary between the territory of the
United States and
Spain, in accordance with a treaty.
From Sept. 1, 1813, until his death, Aug. 29, 1820, he was professor of mathematics and civil engineering at
West Point.