The only American President who fought a duel was Andrew Jackson, who was known to have fought several, including one where he killed his opponent, Charles Dickinson. The exact number of duels is uncertain. Several are well attested to, but his opponents, at least, alleged involvement in over 100 either as a participant or as a second, although that number includes both formal encounters as well as non-formal violent engagements such as his shootout with Thomas and Jesse Benton, where he was badly wounded.

Several candidates for President dueled, most prominently perhaps being Henry Clay, who fought two, and which was part of the rhetoric used against him in his unsuccessful campaign for President in 1844, with some possible impact, although that is hard to gauge.

Abraham Lincoln didn't fight a duel, but did get embroiled in an affair of honor that came close enough to culmination that he and his erstwhile opponent were at the field of combat before it was eventually called off. A dispute over articles lampooning James Shields, alleged to have been written by Lincoln, had brought the two men to this point, but neither had much stomach for the matter leading to it being dropped for reasons of which there are several accounts.