Gallagher played Tom Sawyer as a child actor at the Delaware Children's Theatre.

It played firstly on 15 October 1912 at Wallack's Theatre, New York.

In London, it played at His Majesty's Theatre, opening on September 21, 1927, and ran for 213 performances.

The work played at Daly's Theatre in 1884 and 1900 on Broadway in New York.

In 2010, it played its ten-thousandth performance in London, at Queen's Theatre.

In 1922, the play was adapted as a comic opera by Reginald Somerville and played at the Queen's Theatre.

The play took him only a week to complete, but it played to packed houses at St Martin's Theatre from November 1925 to March 1927.

It also played with success at Wallack's Theatre in New York.

His first professional production was called Dido, a burlesque played at the St. James's Theatre in 1860.

It first played at Wyndham's Theatre on 27 January and went on to be a long-running success.