Does the motion picture, Yankee Doodle Dandy, provide an accurate description of George Cohan's life?

Despite the goal to portray Cohan's life, the movie was far from the truth. In fact when Cohan left the premiere, he said, "It was a good movie. Who was it about?" Although Cohan's life was very interesting, and he did win the Congressional Medal of Honor, the studio felt that his story needed to be "improved" for audiences.