Born in Mason County, Kentucky, Reed established a legal practice in Maysville, Kentucky and won election to the Kentucky House of Representatives. He attended law school but did not graduate, making him the latest-serving Supreme Court Justice who did not graduate from law school. After serving in the United States Army during World War I, Reed emerged as a prominent corporate attorney and took positions with the Federal Farm Board and the Reconstruction Finance Corporation. He took office as Solicitor General in 1935, and defended the constitutionality of several New Deal policies.