Born in Virginia, John Marshall Clemens studied law and was licensed to practice in 1822. He married Jane Lampton of Kentucky in 1823. In 1827 the Clemenses relocated to Jamestown, Tennessee, where Clemens opened a store and eventually became a clerk of the county court. With an eye to the family’s future, he purchased about seventy-five thousand acres near Jamestown; the investment never yielded any return but frustration and bitterness to the next generation. In 1835 Clemens moved his family to Missouri, settling first in the village of Florida, where SLC was born, then in 1839 moving to Hannibal, where Clemens kept a store on Main Street and was elected justice of the peace. He was regarded as one of the foremost citizens of the county, scrupulously honest, but within his family circle he was taciturn and irritable. His sudden death from pneumonia in 1847 left the family in genteel poverty. When his father died SLC was only eleven; he later wrote that “my own knowledge of him amounted to little more than an introduction.”