Ulysses S. Grant wrote his autobiography to support his family after his death according to the book’s description below:
https://www.amazon.com/American-Ulysses-Life-S-Grant/dp/1400069025
For people interested in the Civil War and its aftermath, this looks like a fascinating read.
By Ruth Paget, author Eating Soup with Chopsticks and Marrying France and developer of the Novgorod and Bento War Games