In October 1813, Napoleon was defeated in the Battle of Leipzig. On April 11, 1814, Austria, Russia and Prussia formed an alliance, signing the Treaty of Fontainebleau. The treaty removed Napoleon as emperor of France, exiling him to the isle of Elba. He would not return until February 26, 1815.
Without the distraction of Napoleon, the British could pay more attention to the war with the United States. Out of necessity, Congress repealed the detested Embargo of 1813, on April 14, 1814.
In June 1814, the British began a blockade of ports in Massachusetts. In July, the British captured parts of Maine. Citizens in the occupied territories were forced to swear allegiance to King George. On August 31 New Englanders received news that the British captured Washington burning the Capitol and White House.
How New Englanders Reacted to the British
Look for it Monday, August 4
 Samuel Eliot Morison, “Our Most Unpopular War” Proceedings of the Massachusetts Historical Society, Third Series, V. 80 (1968) 45.