One of the most famous autographed baseballs in history -- the one signed by Babe Ruth with a promise to hit a home run for an ailing 11-year-old boy -- was sold for $250,641 by Grey Flannel Auctions on Thursday night.

An official with the auction house said the buyer wishes to remain anonymous.

Johnny Sylvester, who was injured when he fell off a horse in the summer of 1926, received the autographed ball that had the message "I'll knock a homer for Wednesday's game" written on it.

Ruth then famously hit three home runs for the New York Yankees that Wednesday, which happened to be Game 4 of the 1926 World Series. Newspaper accounts at the time soon proclaimed that Sylvester's condition suddenly improved thanks in part to the moment.

The ball, which was owned by Sylvester's son John Jr., was on loan to the Babe Ruth Birthplace and Museum in Baltimore for 25 years.