Adams and Jefferson were the only signers of the Declaration of Independence who were also elected president.
Adams beat Jefferson in the election of 1796, but since Jefferson was the runner-up, he became Adams's vice president. When Adams ran for a second term in 1800, two major political parties had emerged: the Federalists and the Democratic-Republicans. (Federalists endorsed a strong central government and tended to support Northeastern commercial interests; Democratic-Republicans favored less federal power and tended to support the interests of Southern landholders and the nation's artisans and small farmers.) Adams's decision not to go to war with France in 1799 isolated him within his Federalist Party and he subsequently lost to the more organized Democratic-Republicans, led by Jefferson.
It was a nasty election and the insults were very personal at times: Adams was accused of being a tyrant determined to enslave the people of the United States and Jefferson was cast as an uncompromising believer in equality for all and as a man who didn't believe in God.
After the bitter election of 1800, do you think Adams and Jefferson were able to be friends again?