3. Barack Obama
The current POTUS was a millionaire well before he was president, but it didn’t happen quickly. He could barely pay his student loans for a decade post-graduation, and it was his career as a writer that earned him his first million. When he was 43, he published Dreams From my Father as a re-issue (originally published in 1995), capitalizing on his foray into politics. As POTUS, he makes $400,000 per year, but before that he’d already earned $4.6 million as an author.