Born near Dyersburg, Tennessee, Benton attended two west Tennessee academies and Saint Louis University. He was graduated from the Cumberland School of Law at Cumberland University, Lebanon, Tennessee, in 1870. He served in the Confederate States Army during the Civil War. He was admitted to the bar and commenced practice in Neosho, Missouri. He served as prosecuting attorney of Newton County, Missouri, from 1878 to 1884 and subsequently the United States attorney from March 1885 to July 1889. He also served as delegate to the 1896 Democratic National Convention. On June 24, 1888 he married Elizabeth Wise of Waxahachie, Texas.