Andrew Ellicott was a surveyor employed by President George Washington to survey the boundary lines of the federal Territory of Columbia, which became the District of Columbia. His survey team included his younger brother Joseph and Benjamin…

Banneker was a free African American surveyor, mathematician, and almanac author from Maryland. In 1791, he assisted Andrew Ellicott with a survey of the boundaries of the District of Columbia. Among his duties on the survey, Banneker operated the…