George M. Cohan was known as "Mr. Broadway" for revolutionizing American musical theatre in the early 20th century. He began performing as a child in his family's vaudeville act. As an adult, he wrote over 150 shows and published over 300 songs. His 1904 hit "Little Johnny Jones" included popular songs like "Give My Regards to Broadway" and "The Yankee Doodle Boy." Cohan produced over 50 plays and musicals from 1904-1920 that helped establish the book musical format still used today. His songs became American standards and he is considered a pioneer of integrating dance into musicals to advance the plot.