Which U.S. president's memoirs did Mark Twain publish?

Mark Twain published the memoirs of Ulysses S. Grant.

The book, formally titled Personal Memoirs of U. S. Grant, was written by the former Union general and 18th president during the final year of his life. Grant was suffering from terminal throat cancer and needed income for his family after a disastrous business failure and bankruptcy.

Twain, whose real name was Samuel Clemens, was Grant’s friend. He objected to an early publishing offer that would have paid Grant only a 10-percent royalty and persuaded him to work with Charles L. Webster & Company, a publishing house connected to Twain. Twain also organized an ambitious subscription campaign aimed especially at Civil War veterans.

Grant completed the manuscript shortly before his death in July 1885. The two-volume memoir was published after his death in 1885 and 1886, and it became a major commercial and literary success. A common mix-up is crediting Twain as the memoir’s author: Twain edited and published it, but Grant wrote it.