By the time he was 14 years old, he knew the lines and plots of most classic plays, leading experienced actors to refer to him as "the human prompt book".

[4] When his father died and left his entire estate of $130,000 for constructing a memorial temple in New York City, Thompson decided to become an actor.

[7] In 1908, he told a reporter, "I had just as soon portray for 20 minutes a character in vaudeville, if only it be worthy, as to play a role in a five-act drama.

[10] Shortly after his death, The Brooklyn Daily Eagle said, "for twenty years he was acknowledged as the best character actor in New York.

"[11] After he had rejected offers to appear in films, Thompson took on the role of Andrew Cameron, uncle of the title character in Peggy (1916).