Sherwood Dixon was born in Dixon, Lee County, Illinois, the son of Henry S. and Margaret Casey Dixon. He was the great grandson of the founder of Dixon, "Father" John Dixon. Dixon was a 1920 graduate of the University of Notre Dame, a veteran of World War I and a brigadier general in the Illinois National Guard. Dixon was a member of the Illinois Democratic State Central Committee (1938), a delegate to the 1952 Democratic National Convention and an alternate delegate to the 1940 and 1956 Democratic national conventions.