Cox was appointed and then elected judge of the superior court of the Albany circuit and served from 1912 until 1916, when he resigned and unsuccessfully challenged the incumbent, Frank Park, for the Democratic nomination to represent Georgia's 2nd congressional district in the 65th Congress.
Cox was appointed and subsequently elected judge of the superior court of the Albany circuit, serving from 1912 to 1916, when he resigned and ran unsuccessfully against incumbent Frank Park for the Democratic nomination to represent Georgia's 2nd congressional district in the 65th Congress.