Imbrie attended Friends Select School, Central High School, George Washington University, (A.B. 1902; LL.B. 1905) and Yale Law School . The topic of his master’s thesis was admiralty law. In 1907 he was appointed attorney-in-charge of the Seaman’s Branch of the Legal Aid Society in New York City. In 1908, Imbrie opened a law practice in Baltimore with Howard McCormick, who later served as a long-time professor of English at the United States Naval Academy.