Adams then ran for a seat in the U.S. Senate, which he won in 1803 as a Federalist. As a U.S. senator, Adams once again showed his independent streak by supporting some major political moves by Democratic-Republican President Thomas Jefferson. Adams supported both the Louisiana Purchase and the Embargo Act of 1807. The support of the Embargo Act, which harmed shipping interests in New England, caused the Massachusetts legislature to call for his dismissal. Adams resigned his position in June 1808.