In 1966, Thomas Hoepker and his second wife, journalist Eva Windmoeller, followed Muhammad Ali around Chicago as he prepared for an upcoming fight. Ali retained the heavyweight title in five fights that year — notching three TKOs, one KO, and one unanimous decision. Hoepker’s portrait of the fighter jumping atop a bridge on the Chicago River was spontaneous rather than pre-planned, with Hoepker noting, “That just happened. We were crossing and they said, ‘Hey that’s a nice view!’ And he got out and jumped on that bridge and took off his shirt, that was just to show off, and then he jumped. Once, you know? He jumped once and that was it. Today you would bring a producer and crew, and he would jump 25 times.”