Who designed the original 1791 plan for Washington, D.C., the United States capital?

Pierre Charles L'Enfant designed the original 1791 plan for Washington, D.C., the United States capital.

L’Enfant was a French-born military engineer and artist who served with the Continental Army during the American Revolutionary War. President George Washington appointed him in 1791 to plan the new federal city on the Potomac River after Congress selected the capital’s location.

His design combined a rectangular street grid with broad diagonal avenues, open spaces, and prominent sites for the Capitol and the President’s House. The plan helped create Washington’s distinctive layout, including avenues that cross the grid at angles and produce many triangular and rectangular public spaces.

L’Enfant’s work is often confused with later surveying and revisions. Andrew Ellicott helped survey and revise the plan, while Benjamin Banneker assisted with astronomical calculations and surveying. The basic city plan, however, is known as the L’Enfant Plan.