Frank taught at Bryn Mawr College as a Professor of Latin from 1904 until 1919, when he moved to the Johns Hopkins University.

Frank believed that Rome's imperialism stemmed from a desire to keep peace in the Mediterranean world by preventing the rise of any rival power.

[1] Frank's other work focused on classical literature, with articles on Cicero, Strabo, Curiatius Maternus, Plautus, and Virgil, among others.

[2] He wrote periodically for the American Historical Review, including a paper on the demise of the various ancient Italian peoples that comprised the Roman ethnicity in Julius Caesar's day.

At Johns Hopkins, Frank trained Thomas Robert Shannon Broughton, with whom he collaborated on his studies of the Roman economy.