Conversation so far:
What did George M. Cohan do first?
George M. Cohan began his career as a child, performing with his parents and sister in a vaudeville act known as The Four Cohans.
How many skits did George M. Cohan write?
George M. Cohan began writing over 150 original skits and songs.
Who did George M. Cohan write these for?
George M. Cohan wrote them for the family act in both vaudeville and minstrel shows while in his teens.
When did George M. Cohan write over 150 original skits and songs in his early career?
The Four Cohans mostly toured together from 1890 to 1901. George M. Cohan and his sister made their Broadway debuts in 1893 in a sketch called The Lively Bootblack.
What was George M. Cohan's next accomplishment after the Lively Bootblack?
George M. Cohan wrote, directed and produced his first Broadway musical

Question: When did he write his first musical?
Self-contained rewrite: When did George M. Cohan write his first musical?