Reuben Davis attended public schools and studied medicine briefly before turning to law. He was admitted to the bar in 1834 and began practicing law in Aberdeen, Mississippi. Davis held various judicial and legislative positions, including serving as a prosecuting attorney and a member of the Mississippi House of Representatives. He also served in the military during the Mexican–American War and the American Civil War, reaching the rank of Brigadier General. Davis authored *Recollections of Mississippi and Mississippians* and owned slaves as documented in census records.

Reuben Davis's political career is marked by a steadfast commitment to Southern interests, evident in his military service during both the Mexican-American War and the Civil War. Despite his shifting political affiliations—from Whig to Democrat to Greenbacker—Davis consistently advocated for regional causes, revealing a highly localized approach. His ownership of an increasing number of slaves through the 1840s and 1850s, coupled with his unrepentant stance post-Civil War, highlights a deeply entrenched Southern identity that resists ideological compromise.