January–March • January 3 – The Treaty of Hopewell is signed between the United States of America and the Choctaw Nation. • January 10 – The Treaty of Hopewell is signed between the United States of America and the Chickasaw Nation. • January 31 – The Treaty of Fort Finney, is signed on January 31, 1786, between the United States and certain leaders of the Shawnee. • March 26 – Columbia, South Carolina is chartered as the first planned city in the United States. April–June • June 25 – Gavriil Pribylov discovers St. George Island of the Pribilof Islands in the Bering Sea. July–September • August – James Rumsey tests his first steam boat in the Potomac River at Shepherdstown Virginia (now West Virginia). • August 29 – Shays' Rebellion begins in Massachusetts. • September 11-14 – Annapolis Convention October–December • November 7 – The oldest musical organization in the United States (the Stoughton Musical Society) is founded. • December 4 – Mission Santa Barbara is founded by Father Fermín Francisco de Lasuén, becoming the 10th mission in the California mission chain. Undated • The town of Martinsborough, North Carolina, itself named for Royal Governor Josiah Martin in 1771, is renamed "Greenesville" in honor of United States General Nathanael Greene by the North Carolina General Assembly; the name "Greenesville" is later shortened to become Greenville. • Beginning Point of the U.S. Public Land Survey established. • The United States pays protection money to the Sultan of Morocco to ensure the safety of American merchantmen in the Mediterranean Sea from Barbary pirates. Ongoing • Articles of Confederation in effect (1781–1788) • Northwest Indian War (1785–1795) ==Births==

1786 in the United States