Which MLB team was the first to put numbers on the players' backs in a game?

The Indians wore numbered uniforms on April 17, 1929, becoming the first MLB team to wear uniforms with numbers on the back. The Yankees had planned to debut numbered uniforms the previous day but were rained out. The first game with both teams wearing numbered uniforms was between the Indians and Yankees on May 13, 1929. The 1937 Philadelphia Athletics were the last team to wear numbers on both their home and road uniforms.

In 1916, the Indians wore uniforms with numbers on the left sleeve. It is rumored the first official record of a team wearing numbers was the 1907 Reading Red Roses of the Atlantic League. There is also a photo published in the Chicago Daily News in 1909 showing Jose Mendez off the Cuban Stars sporting a uniform with a number on the left sleeve.

The 1960 White Sox was the first team to put names on the back of uniforms.