St. Louis Lambert International Airport serves a hub for what American airline with its headquarters in Cocord, Missouri?
St. Louis Lambert International Airport:  It is a focus city for Southwest Airlines, and was a former hub for Trans World Airlines and later for American Airlines. Air Choice One: Multi-Aero, Inc., doing business as (d/b/a) Air Choice One, is an American airline with its headquarters in Concord, Missouri in Greater St. Louis.
Air Choice One