Four children were born to Samuel Langhorne Clemens and Olivia Louise Langdon (his wife): Langdon Clemens (1870-1872), Olivia Susan Clemens (1872-1896), Clara Langdon Clemens (1874-1962), and Jane Lampton Clemens (1880-1909). Clara Clemens was the only surviving child of Samuel Clemens. She married Ossip Gabrilowitsch, and had one child, Nina Clemens Gabrilowitsch (1910-1966).
Twain's direct family line ended when Nina died in 1966, with no children.
Mark Twain - Extended Family Tree?
- Lampton, Lucius. "The Geneology of Mark Twain." Jackson, MS: Diamond L. Publishing, 1990.
- Rasmussen, R. Kent. "Mark Twain A to Z: The Essential Reference to His Life and Writings." Oxford: Oxford UP, 1996.