Final answer:
The War of 1812 had a negative impact on the Federalist Party's efforts to change the Constitution, leading to its downfall.
Step-by-step explanation:
The outcome of the War of 1812 had a significant impact on the Federalist Party's efforts to change the Constitution. The war was very unpopular in New England, which was a stronghold for the Federalists. The December 1814 Hartford Convention, where some Federalists called for New England to secede from the United States, discredited the party and led to its downfall. The Federalists would never regain the trust and confidence of the American people, and the party would fade from the political scene.