Reuben Davis was born in Winchester, Tennessee, in 1813 and later moved to Alabama. He studied medicine briefly before transitioning to law, and was admitted to the bar in 1834, commencing practice in Aberdeen, Mississippi. Davis served as prosecuting attorney for the sixth judicial district and later as a member of the Mississippi House of Representatives. He held congressional positions as a Democrat and represented Mississippi in the 1st Confederate States Congress. Davis also served in the military, participating in the Mexican–American War and volunteering as a Brigadier General during the American Civil War.

Reuben Davis's political philosophy is marked by a steadfast advocacy for states' rights in economic matters, juxtaposed with his support for protective tariffs to benefit Southern industries. His military service in both the Mexican–American War and the American Civil War, coupled with his representation of Mississippi in the Confederate Congress, underscores a deep-rooted commitment to regional interests. Davis's expansion of his slaveholding from four to 42 between 1840 and 1860 reflects a complex stance on slavery, one that aligns with the economic and social norms of his time. His political career, spanning Whig, Democrat, and Greenback affiliations, reveals an ideologically agile approach, navigating and sometimes converging with opposing factions to protect regional industrial interests.