He was born on November 30, 1835, the fifth child of John Marshall and Jane (Lampton) Clemens, both descendants of Virginians. His birthplace was Florida, Missouri, a village to which the family had moved the previous June. The boy’s father, a storekeeper and at times a lawyer, had little talent of money making and failed there as he had elsewhere. The Clemenses therefore moved in the fall of 1839 to Hannibal, Missouri.