3rd Infantry Regiment was formed near Pensacola, Florida, in July, 1861. Its companies were recruited in the counties of St. Johns, Hernando, Jefferson, Duval, Wakulla, Madison, Columbia, and Suwannee. The unit served along the coast at Talbot Island and Cedar Keys, then moved to Mobile. After fighting at Perryville it was assigned to Preston's, Stovall's, Finley's, J.A. Smith's Brigade, and during December, 1862, consolidated with the 1st Florida Infantry Regiment.