The First American Regiment (also known as Harmar's Regiment, The United States Regiment, The Regiment of Infantry, 1st Sub-legion, 1st Regiment of Infantry and 1st Infantry Regiment) was the first peacetime regular army infantry unit authorized by the Confederation Congress after the American Revolutionary War. Organized in August 1784, it served primarily on the early American frontier west of the Appalachian Mountains. In 1815, following the end of the War of 1812, it was consolidated with several other regiments to form the 3rd Infantry Regiment.