Following her father's death, the income from Caspary's writing was at times only just sufficient to support both herself and her mother, and during the Great Depression she became interested in Socialist causes. Caspary joined the Communist party under an alias, but not being totally committed and at odds with its code of secrecy, she claimed to have confined her activities to fund-raising and hosting meetings. Caspary visited Russia in an attempt to confirm her beliefs, but became disillusioned and wished to resign from the Party, although she continued to contribute money and support similar causes. She eventually married her lover and writing collaborator of six years, Isidor "Igee" Goldsmith; but despite this being a successful partnership, her Communist connections later lead to her being "graylisted", temporarily yet significantly affecting their offers of work and income. The couple split their time between Hollywood and Europe until Igee's death in 1964, after which Caspary remained in New York where she wrote a further eight books.