sentences:  In 1946, Shaw became the San Francisco 49ers' first head coach in the old All-America Football Conference and continued through 1954; they entered the National Football League in from 1950.After two seasons as the first Air Force Academy varsity head coach (1956–1957), he returned to the NFL in 1958 with Philadelphia.He stepped down after three seasons, following their win in the championship game over Vince Lombardi's Green Bay Packers.