In the series finale, a retired Adams begins work on his memoirs. Despite several family tragedies, he also embarks on mending his friendship with Jefferson through a series of letters and lives long enough to see his son John Quincy become president.
As president, Adams tries to keep the U.S. out of war with France. But his retention of Washington's cabinet and his support for the Alien and Sedition Acts of 1798 cause much controversy and effectively end his bond with Jefferson; Adams is bitter after the death of one of his sons, but sets his sights on reelection after moving to the country's new capital city.
Now serving as vice president, Adams is dismayed by his inconsequential role in the government, and finds his friendship with Jefferson suffering as a result of the conflict between England and France. In 1797, Adams succeeds Washington as president, but needs Abigail's help to make sense of this important position and the future of the country.
In 1781, while recovering from an illness in Holland, Adams is informed of Cornwallis's surrender to Washington and is eventually reunited with Abigail in Paris. Later, Adams meets King George III while serving as ambassador to England, finally returns home to Boston and his now-grown children, and considers a position in the new government.
British attacks on Lexington and Concord in 1775 spur debate among the Continental Congress, but Adams' arguments on behalf of Massachusetts---and independence---are met with skepticism by some of his colleagues.