"Ellery Queen" was "born" in 1928 when the two Brooklyn-born cousins, Frederic Dannay and Manfred B. Lee, themselves both born in 1905, decided to enter a mystery-novel contest sponsored by McClures magazine. The rules required that entries be submitted under a pseudonym and the cousins, believing that readers would remember an author if the name also appeared throughout the book, chose Ellery Queen because it seemed unusual and memorable to them. Dannay and Lee were familiar with choosing pseudonyms; they had each changed their names, from Daniel Nathan and Manford Lepofsky, as young men. Just before Dannay and Lee were awarded first prize for their submission, McClures went bankrupt, but the story, The Roman Hat Mystery, was published in 1929 by the Frederick A. Stokes Company, thus launching the career of Ellery Queen. The creation of a detective who was also a writer of mystery stories proved to be extremely popular, and Ellery Queen eventually amassed a reported 120 million readers.

The typescript of The Roman Hat Mystery is inscribed on the title page by Dannay: "This is the only carbon-copy of the original typescript of ‘The Roman Hat Mystery' still in existence. The original typescript, and all other carbon copies, were destroyed.-Ellery Queen 12/22/41." It and the majority of Columbia's Ellery Queen papers were given by Frederic Dannay's sons, Richard and Douglas. Their gift also included the files of Ellery Queens Mystery Magazine, containing some 4,600 manuscripts submitted to the magazine over a period of 40 years, nearly all with Dannay's manuscript corrections.