Tommy McCoy grew up poor and scrappy. As a young man he discovers that he can fight with his powerful right arm. He becomes successful at boxing, however he has an alcoholic father.
Overall a decent boxing flick with Mickey Rooney playing his regular part: scrappy, down, up, down and then in love. The weakest points are when some very improbable (and unnecessary) plot choices are used that make me cringe (like expecting a very alcoholic braggart of a father to keep a secret). But what can you expect from a B Mickey Rooney flick?