The Chesapeake
Chesapeake was an event when the US boat that was intercepted by a British boat named leopard and had a small skirmish that almost caused war while Jefferson (pacifist) didn’t want to declare war. America almost went to war with Britain but war of 1812 didn’t happen until few years later and was not caused during the presidency of Thomas Jefferson.
http://www.slidego.com/res/palooza/america/WarOf1812/2DE61DFA.jpg