Last updated: April 5, 2019
Article
Andrew Ellicott
![853 line drawing of man](/articles/images/853.png)
Photo: Library of Congress
Ellicott taught mathematics in Baltimore prior to the Revolutionary War. Afterwards, he surveyed large areas where borders were still being established, including the Mason-Dixon line between Pennsylvania and Maryland. He made the first topographical study of the Niagara River and falls, and between 1791 and 1793 he surveyed the “Federal City,” redrawing Pierre L’Enfant’s design.
A member of the American Philosophical Society, Ellicott had knowledge of the frontier and experience dealing with Native peoples, which made him an ideal person to train Lewis. They set to work on April 20, using a sextant, chronometer, and other instruments for recording celestial movements. The practice sessions took longer than anticipated, and it was not until May 7 when Lewis was able to move on to Philadelphia and his studies continued with other scientists.
Ellicott continued to accept surveying commissions, but was seldom rewarded adequately for his work. As such, he suffered financially. In 1813, he accepted a post as professor of mathematics at the young West Point Academy. He died at West Point on August 20, 1820 at the age of 66.