The New York Yankees were the first.
The 1916 Cleveland Indians who had the number on the left sleeve of home uniforms.
New York Yankees
The first major league in baseball was the National Association whose first year was 1871.
The Cincinnati Reds, is recognized as the first "professional" baseball team.
first to play
The first major league, the National Association, started in 1871. The National League's first year was 1876 and the American League's first year was 1901.
Michael lohman
Yes
Jackie Robinson
Chicago Cubs
Because the National League has been in existence longer than the American League ... the National League's first season as a major league was 1876 and the American League's first season as a major league was 1901.