On 2 February 1901, Congress authorized the organization of the Twelfth Regiment of Cavalry, Army of the United States. Under this authority, the regiment was formed at Fort Sam Houston, Texas on 8 February 1901.
From 1901 until 1911, the regiment served posts in Texas, Georgia, and the Philippines.
During World War II the 12th Cavalry served as an infantry regiment within the 1st Cavalry Division.