Mary Todd Lincoln's three-piece purple velvet ensemble is thought to have been made by black dressmaker Elizabeth Keckley. Mrs. Lincoln is shown as an influential anti-slavery advocate who supported Union troops. (Photo courtesy Smithsonial National Museum of American History)

Mary Todd Lincoln's three-piece purple velvet ensemble is thought to have been made by black dressmaker Elizabeth Keckley. Mrs. Lincoln is shown as an influential anti-slavery advocate who supported Union troops. (Photo courtesy Smithsonial National Museum of American History)