[2] At the latter, he was a member of Phi Beta Kappa Society, gained experience in musical theater and finished as a magna cum laude graduate.

[citation needed] McCormick's performance of sailor Luther Billis won him a Tony Award in 1950 for best supporting or featured actor in a musical.

[citation needed] McCormick's other Broadway credits include 27 Wagons Full of Cotton (1954), Joy to the World (1947), Soldier's Wife (1944), Storm Operation (1943), The Damask Cheek (1942), Lily of the Valley (1941), Thunder Rock (1939), In Clover (1937), The Wingless Victory (1936), Hell Freezes Over (1935), How Beautiful with Shoes (1935), Substitute for Murder (1935), Paths of Glory (1935), and Carry Nation (1932).

[6] McCormick portrayed Charlie, the partner of pool shark "Fast Eddie" Felson (Paul Newman) in The Hustler (1961).

He also made guest appearances on numerous television programs of the 1950s/early 1960s, including The Untouchables, Naked City, Alfred Hitchcock Presents, The Donna Reed Show, Way Out and The Iceman Cometh (1960 TV production), McCormick was also known for his portrayal of "Colonel Ralph Bryant" in the 1949 movie Jolson Sings Again.