M Martin Van Buren

Martin Van Buren (1782–1862), the eighth President (1837–1841), was a skilled politician and organizer who helped found the democratic Party. His presidency, however, was marred by the Panic of 1837, a financial crisis that led to a severe economic depression during his time in office.

Interesting anecdote: Van Buren’s nickname “Old Kinderhook” (from his hometown Kinderhook, NY) gave rise to the popular term “OK.” His supporters formed "OK Clubs" during his campaign, popularizing “OK” as a slogan meaning all is well – a term still used worldwide today.