Choose from one of Dean's Cards Houston Astros Team Sets. The Houston Astros, originally nicknamed the Colt .45s, become the Astros in 1965. The Houston Astros moved to the American League in 2013, after 41 years in the National League. Houston Astros' players who were eventually inducted into Baseball's Hall-of-Fame include: Joe Morgan, Nolan Ryan, Jeff Bagwell and Craig Biggio.