 After the war, he was a delegate to the State constitutional convention in 1865.MacIntyre was elected in 1870 as a Democrat to the U.S. House of Representatives to the 42nd Congress.He served one term from March 4, 1871 until March 3, 1873 and did not run for reelection in 1872

After his congressional service, MacIntyre continued practicing law in Thomasville.