He left Puerto Rico as a child and grew up mostly in New York's Harlem neighborhood, one of the reasons he later earned the nickname "the Harlem Heckler."
He went on to win super lightweight, lightweight and junior welterweight world titles in the 1980s.
Camacho has fought other high-profile bouts in his career against Felix Trinidad, Julio Cesar Chavez and Sugar Ray Leonard. Camacho knocked out Leonard in 1997, ending what was that former champ's final comeback attempt.
Camacho has a career record of 79-6-3.
In recent years, he has divided his time between Puerto Rico and Florida, appearing regularly on Spanish-language television as well as on a reality show called "Es Macho Time!" on YouTube. In San Juan, he had been living in the beach community of Isla Verde, where he would obligingly pose for photos with tourists who recognized him on the street, said former pro boxer Victor "Luvi" Callejas, a neighbor and friend.
"We all know what Macho Camacho has done, but in the last couple of months he hasn't been in any trouble," Callejas said as he kept vigil outside the hospital. "He has been taking it easy. He's been upbeat."
Drug, alcohol and other problems have trailed Camacho since the prime of his boxing career. He was sentenced in 2007 to seven years in prison for the burglary of a computer store in Mississippi. While arresting him on the burglary charge in January 2005, police also found the drug ecstasy.
A judge eventually suspended all but one year of the sentence and gave Camacho probation. He wound up serving two weeks in jail, though, after violating that probation.
His wife also filed domestic abuse complaints against him twice before their divorce several years ago.
Associated Press writer David Skretta in Kansas City contributed to this report.
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