On September 15, 1789, Congress passed "An Act to provide for the safekeeping of the Acts, Records, and Seal of the United States, and for other purposes." This law changed the name of the Department of Foreign Affairs to the Department of State because certain domestic duties were assigned to the agency. These included:
Other domestic duties that the Department was responsible for at various times included issuance of patents on inventions, publication of the census returns, management of the mint, control of copyrights, and regulation of immigration. Most domestic functions have been transferred to other agencies. Those that remain in the Department are: preparation and authentication of copies of records and authentication of copies under the Department's seal, storage and use of the Great Seal, performance of protocol functions for the White House, drafting of certain Presidential proclamations, and replies to public inquiries.
Benjamin Franklin was the first U.S. diplomat. He was appointed on September 26, 1776 as part of a commission charged with gaining French support for American independence. He was appointed Minister to France on September 14, 1778 and presented his credentials on March 23, 1779, becoming the first American diplomat to be received by a foreign government. Franklin was one of three Commissioners who negotiated the peace treaty with Great Britain, and continued to serve in France until May 17, 1785.
The first U.S. treaty to be signed was the Treaty of Amity and Commerce with France that was signed in Paris on February 6, 1778.
The oldest diplomatic property owned by the United States is the U.S. Legation building in Tangier. The Sultan of Morocco made a gift of the building in 1821. It served as the U.S. Consulate and Legation until 1956. It is currently preserved as a museum and study center.