What he did is not only one of the most historic moments in sports, but in history. The Racism, Hatred, etc that he faced has been documented. However, there is another man who also made his Major League debut that same season but in the American League with The Cleveland Indians and faced the same problems that Jackie did but is now forgotten for the most part. His name was Larry Doby. Doby is important because it made it possible that Jackie Robinson was not the last.
You have to remember, there was no Interleague Baseball in the 1940's so Doby faced what Robinson did but in a lot of Stadiums that Robinson never played in. Doby made his Major League debut on July 5, 1947 after being signed from the Newark Eagles of the Negro Leagues. Just because Doby was the second man, does not mean that what he faced was any less than what Robinson did, nor are his contributions.
I believe that The Indians should have a Larry Doby Weekend honoring him in July every season.
Here are links where you can learn more about Larry Doby.
Wikipedia - Baseball Hall of Fame - Baseball-Reference.com