Many presidents of the United States have written autobiographies about their presidencies and/or (some periods of) their life before their time in office. Some 19th-century U.S. presidents who wrote autobiographies are James Buchanan and Ulysses S. Grant, though Grant's autobiography is about his time as General during the U.S. Civil War and not about his presidency. Some of the more recent U.S. presidential autobiographies, such as Bill Clinton's, George W. Bush's, and Barack Obama's (written and published before he was elected president) sold well enough to earn them millions of dollars.