He is best known for his work Anthony Adverse (made into a 1936 movie of the same name), regarded by many critics "as the model and precursor of the contemporary American historical novel.

[2] Allen received a BS in economics from the University of Pittsburgh in 1915[3] where he contributed to the humor magazine The Pitt Panther.

[5] Allen served as a 2nd lieutenant in the 18th Pennsylvania Infantry on the Mexican border in 1916 during the Pancho Villa Expedition.

For a period of time, he taught at the Porter Military Academy in Charleston, South Carolina.

Allen also wrote Israfel (1926), a biography of American writer Edgar Allan Poe.

Allen was a good friend of Marjory Stoneman Douglas and instigated her writing The Everglades: River of Grass.

[3] Allen died at his home, called the Glades, in Coconut Grove, Florida,[6] at the age of 60, from a heart attack, and was found by his wife.