What president wrote a best selling autobiography?

It's difficult to definitively say which president wrote the best-selling autobiography, as sales figures can be tricky to compare across different eras and formats. However, some contenders for the title include:

* Theodore Roosevelt: His autobiography, published in 1913, was a major success and is still considered a classic.

* Harry S. Truman: His two-volume autobiography, published in 1955 and 1956, became a best-seller and is considered one of the most candid presidential memoirs ever written.

* Bill Clinton: His autobiography, "My Life," published in 2004, was a massive commercial success, selling over 3 million copies in its first week alone.

It's also worth noting that Barack Obama's "Dreams from My Father" and "The Audacity of Hope" were both best-selling books before his presidency.

Ultimately, the answer to your question depends on how you define "best-selling" and what criteria you use to compare different books.