Negro Leagues Baseball Museum spokesman Bob Kendrick said the seven-sentence letter, purchased at a March auction for $21,000 by businessman Jeffrey Gitomer, allows the reader a small insight into the life of a black baseball player at the cusp of the game's integration, The Charlotte (N.C.) Observer reported Sunday.

"That letter -- that's where the light goes on for people," Kendrick said. "All of a sudden, these stories start to ring a little more true."

Aaron entered Major League Baseball in 1954 when black players were not accepted by much of general society, and went on to star for the Milwaukee and Atlanta Braves before finishing his Hall of Fame career with the Milwaukee Brewers. The letter was written in 1951 when a 17-year-old Aaron got a chance to first play for a Negro American League team, the Observer said.

In the letter, Aaron informs Syd Pollack he will be able to join his Negro team, the Indianapolis Clowns.

"Dear Mr. Pollack," Aaron writes. "I receive you letter, and it is entirely satisfactory with my parents Mr. & Mrs. Aaron, that I may join the Indianapolis Clowns next season."