The 3rd Battalion, 1st Infantry was constituted March 3, 1791 in the Regular Army as a company of the 2nd Infantry. The unit has participated in the Indian Wars, the War of 1812, the Mexican War, the Civil War, the War with Spain, the Philippine Insurrection, World War II, and was activated July, 1966 in Hawaii to be assigned to the 11th Infantry Brigade in the Vietnam Campaign.
The battalion arrived in-country on December 22, 1967 landing at the Port of Qui Nhon after a 16 day trip by troop ship from Hawaii. The battalion's base camp was located at Fire Support Base Bronco, next to village of Duc Pho, in the southern portion of South Vietnam's I Corps.
The unit was organized as a lightly equipped quick reaction unit which could move by any means of transportation to meet and defeat the enemy in any environment.
The battalion motto "Semper Primus, Always First" describes the spirit and determination that have always been associated with the unit.
Soldiers of the 3rd Battalion, 1st Infantry were awarded over 2,000 medals during 1969. Nearly 500 awards were given for valorous actions.
The 3rd battalion, 1st Infantry has received the distinguished Unit Citation, the Philippine Presidential Unit Citation, and the Combat Infantry Streamer.
Source: the americal division, "under the southern cross" - published by the U.S. Army in 1971.