Final answer:
Washington D.C. was chosen as a result of the Compromise of 1790, a political agreement between Alexander Hamilton, Thomas Jefferson, and James Madison, which also involved Congress passing the Residence Bill to establish the District of Columbia as the capital.
Step-by-step explanation:
The sight for Washington D.C. was chosen as part of a political compromise struck between Alexander Hamilton, who was the Secretary of the Treasury at the time, and prominent Virginians Thomas Jefferson and James Madison. This agreement is today known as the Compromise of 1790. The decision was heavily influenced by the politics of the time, especially regarding the federal government assuming state debts. Hamilton had proposed federal assumption of state debts left from the Revolutionary War, and in return for support from southern states, he agreed to support a southern location for the nation's capital.
Congress passed the Residence Bill in July 1790, after the compromise, which temporarily moved the capital to Philadelphia for ten years with the intention to construct the actual capital on the banks of the Potomac River, an area carved out from Virginia and Maryland.
The location of Washington D.C. was also selected while keeping in consideration that the U.S. needed to have a national capital that was not part of any state, which led to the establishment of the District of Columbia as an independent territory. The selection of this site was authorized under Section 8 Clause 17 of the U.S. constitution, granting Congress the power to create a national capital outside state jurisdiction.
\