Homer S. Cummings was born April 30, 1870, in Chicago, Illinois. He attended Yale College and Yale Law School, graduating in 1893, and was admitted to the Connecticut bar the same year. He began his career at a law firm in Stamford, Connecticut, before serving two terms as mayor of Stamford (1900-1902 and 1904-1906).In 1909, he established a law firm with Charles D. Lockwood, where he practiced until becoming attorney general in the presidential administration of Franklin D. Roosevelt. Cummings was also a member of the Democratic National Committee, representing Connecticut from 1900 to 1925 and serving as committee chairman from 1919 to 1920.

Originally, President Roosevelt chose Cummings to serve as governor-general of the Philippines, but the sudden death of Senator Thomas J. Walsh prompted his appointment to the Department of Justice. After resigning his cabinet post in January 1939, Cummings returned to practicing law. He died on September 10, 1956.