When the Yalta accord was signed in 1945, the Lenczowskis refused to serve in Stalin's communist government in Poland and sought refuge in the United States. After a year of graduate study at Johns Hopkins University, and occasional work for the Foreign Broadcasting Division of the Department of State, Lenczowski found employment as instructor, and later assistant professor, at Hamilton College in New York State. It was here that he came to the attention of Peter Odegard, one of the pivotal figures of the discipline of political science of the time and chair of the Berkeley department. He became a U.S. citizen in 1951.