born Aug. 2, 1754, Paris, France
died June 14, 1825, Prince Georges county, Md., U.S.
French-born U.S. engineer, architect, and urban planner.
After studying in Paris, he volunteered as a soldier and engineer in the American Revolutionary Army. Congress made him major of engineers in 1783. In 1791 George Washington had him prepare a plan for a federal capital on the Potomac River. He designed a gridiron of blocks on which broad diagonal avenues were superimposed; focusing on the Capitol and presidential mansion, the plan incorporated green spaces and provided vistas of street intersections where monuments and fountains could be placed. Though he was dismissed in 1792 for his imperious attitude and died in poverty, his plan was later generally followed.