Final answer:
The War of 1812 was caused by British impressment of American sailors, support for Native American resistance to U.S. expansion, and trade interference. It ended with the Treaty of Ghent and had lasting effects including American nationalism, the demise of the Federalist Party, and the onset of the market revolution.
Step-by-step explanation:
The War of 1812, often labeled as the Second War of American Independence, had several underlying causes. A major provocateur of conflict was the British practice of impressment, forcibly enlisting American sailors into the Royal Navy, which represented a blatant disregard for American sovereignty. This, coupled with Britain's support of Native American resistance against U.S. westward expansion and interference with American trade, propelled the U.S. into war. The conflict lasted beyond the year its name suggests, with a formal end coming with the Treaty of Ghent in 1814.
The war's significance reaches beyond these diplomatic and territorial disputes. It led to a surge in American nationalism and the demise of the Federalist Party following the Hartford Convention. The Battle of New Orleans emerged as a symbol of American resilience, despite occurring after peace negotiations had concluded. Moreover, the war ignited the market revolution within the United States, paving the way for increased domestic production and industrial growth, particularly in the North.