Houston Astros enfranchised 1962 in National League as the Houston Colt .45s (team changed name to Astros in 1965), transferred to American League (2013) Los Angeles Angels of Anaheim enfranchised 1961 as the Los Angeles Angels, moved within the Los Angeles area to Anaheim (1966) Oakland Athletics enfranchised 1901* in Philadelphia, moved to Kansas City (1955) and to Oakland (1968) Seattle Mariners enfranchised 1977 Texas Rangers enfranchised 1961 as the Washington Senators, moved to Arlington (1972)[3]