Appointed midshipman on 22 November 1805 and promoted to lieutenant on 13 June 1810, he served in the War of 1812, in operations against Algiers in 1815 and in the suppression of piracy with the West Indies Squadron. Further promotions to master commandant on 5 March 1817 and captain on 24 April 1828 followed.
He established the Pensacola Navy Yard and commanded it from 1832 to 1843. He also commanded the West Indies Squadron, with which he campaigned along the Florida coast and inland during the conflict with the Seminoles beginning in 1835.
Captain Dallas died 3 June 1844 at Callao, Peru.