Which person selected the location which later became the District of Columbia (by act of Congress in 1790)?

The location of the U.S. capital was born from one of the most famous political deals in American history, the Compromise of 1790. In a deal brokered by figures like Alexander Hamilton and Thomas Jefferson, northern states agreed to place the permanent capital in the South. In exchange, southern states agreed to let the federal government assume the states' Revolutionary War debts, a key part of Hamilton's financial plan. The resulting Residence Act of 1790 gave the president the sole authority to select a specific site for a new federal district somewhere along the Potomac River.

As president, George Washington was uniquely suited for this task. A former land surveyor with an intimate knowledge of the Potomac River region, he had long envisioned the area as a future commercial hub. His own estate, Mount Vernon, was just a few miles south of the proposed location. After the act was passed, Washington personally toured several potential sites on horseback, ultimately selecting the ten-mile square of land ceded by Maryland and Virginia that would be named in his honor. He then oversaw the planning and development of the new federal city.