The BBWAA votes to rename the Rookie of the Year Award in honor of Jackie Robinson, who broke baseball’s color barrier on the way to winning the first Rookie of the Year Award in 1947.

On July 14, 1987 The BBWAA votes to rename the Rookie of the Year Award in honor of Jackie Robinson, who broke baseball’s color barrier on the way to winning the first Rookie of the Year Award in 1947.

Source
Baseball Reference July 14