See Photos of Satchel Paige Before He Crossed the Baseball Color Line

Leroy “Satchel” Paige spent two decades pitching in the American Negro leagues before Major League Baseball, in 1947, began to integrate its ranks. When he debuted with the Cleveland Indians in July 1948, he was not only among the first black players in the league; he was also, at 42, the oldest rookie in the Major League.

LIFE profiled Paige in 1941, years before joining the MLB was even a glimmer of a possibility. At that time, Paige pitched as a freelancer, working for whichever team would pay him the most competitive fee. Major League pitchers, the magazine pointed out, typically played every fourth game, but Paige “pitches three games a week all season, winning most of them.”

Though Paige drew crowds mainly thanks to his supreme talent—Joe DiMaggio said after facing him in a 1936 non-league game that Paige was the greatest pitcher he had ever batted against—but his outsize personality also attracted numbers to every game. He was a showman and a storyteller, bestowing playful nicknames upon his pitches (a changeup was a “two-hump blooper” and a medium-speed fastball was a “Little Tom”). And his performance seemed unaffected by his eating habits, which had him “consuming great quantities of ice-cold pop and hotdogs just before pitching.”

In 1971, Paige—who played his last game at the age of 59—became the first Negro leagues player inducted into the National Baseball Hall of Fame.

Liz Ronk, who edited this gallery, is the Photo Editor for LIFE.com. Follow her on Twitter @lizabethronk.