Answer:
1. Jefferson returned to the United States in 1789 to serve as the first secretary of state under President George Washington. He was entering the most uncharted waters in American history. There had never been an enduring republican government in a nation as large as the United States, and no one was sure if it was possible or how it would work.
2. The election of 1800 was one of the most controversial in American history, marked by intrigue, betrayals, and a tie in the electoral college between two candidates who were running mates on the same ticket. The eventual winner was decided only after days of balloting in the House of Representatives.
When it was settled, Thomas Jefferson became president, marking a philosophical change that has been characterized as the "Revolution of 1800." The result represented a significant political realignment as the first two presidents, George Washington and John Adams, had been Federalists, while Jefferson represented the ascending Democratic-Republican Party.
Explanation: