### Instruction: Who was boxer John Baldwin
### Input: Known as "The Mad" Baldwin, he turned pro in 1970 and lost a decision to Marvin Hagler in 1975. In 1977 he took on Rocky Mosley Jr in the ill-fated U.S. Championship Tournament, but lost via K.O. In 1978 he lost a decision to Marvin Johnson, and retired a year later.
### Response: Born in Detroit, John Baldwin was a professional US boxer.  He fought in the Light-Middleweight category and won a bronze medal in the 1968 Olympics.   He turned pro in 1970, and lost a decision to Marvin Hagler in 1975.  He retired in 1979