Benjamin was born in 1808 the ninth child of Martha Jefferson Randolph and Thomas Mann Randolph. He was named after Thomas Jefferson’s friend, Benjamin Franklin, but his family called him "Ben". He studied medicine at the University of Virginia. In 1831, he married Sally Carter of Redlands. Sally received 642 acres upon her marriage. The couple named the farm, Round Top. They had three children.

            Benjamin was a farmer, Virginia state senator, and doctor. He died in 1871 at the age of sixty-three.