The oldest of three children of a single mother, Bella Cohen was born in Bucharest, Romania and with her family emigrated to the Lower East Side of Manhattan when she was a child.

After graduation from Washington Irving High School,[3] she worked as a journalist for socialist and pacifist newspapers such as the New York Call.

In the summer of 1943, Sam accompanied Lt. Burgess Meredith to England to co-write the U.S. Army training film A Welcome to Britain, which educated arriving troops on cultural differences between Americans and the British.

[6] The Spewacks were separated in 1948 when they were approached to write the book for Kiss Me, Kate, which centered on a once-married couple of thespians who use the stage on which they're performing as a battling ground.

Bella initially began working with composer-lyricist Cole Porter on her own, but eventually turned to Sam to collaborate with her, and the Spewacks completed the project together.

[12] A Letter to Sam from Bella, a one-act play by Broadway director Aaron Frankel, is based on the Spewacks' personal papers from the Theater Arts Collection of Columbia University's Rare Book and Manuscript Library.