Final answer:
The described event was a surprise military attack by British forces during the War of 1812 when they burned Washington, D.C. The naval battle between the Leopard and the Chesapeake in 1807 further escalated tensions that contributed to the war.
Step-by-step explanation:
The action described in the question, 'Entered the US in a different route through the Chesapeake Bay and attacked DC,' refers to a surprise military attack during the War of 1812. In July 1814, British forces sailed up the Chesapeake Bay and burned Washington, D.C., including the Capitol and the White House, forcing President Madison to flee. This incident underlines the intense conflict between the United States and Great Britain at the time, which stemmed from various grievances, such as the British policy of impressment (forcing American sailors into the British Navy), trade restrictions imposed by the British, and conflicts over territory.
The naval battle between the Leopard and the Chesapeake occurred in 1807 when the British warship HMS Leopard attacked the American frigate USS Chesapeake, demanding to search the ship for deserters. This act further inflamed tensions between the two nations leading up to the War of 1812, illustrating the British disregard for American neutrality on the seas.