On January 8, 1815, the most famous battle of the War of 1812 occurred when Andrew Jackson defeated the British Army at the Battle of New Orleans. The only problem with the battle was that the War ended on Dec 24, 1814. There are two possible scenarios why the battle happened after the War. One was that Jackson did not know the War was over. This is very likely with the lack of communication at the time. The second scenario was that Jackson did know but did not care and wanted to make sure we were in control of New Orleans after the war. If you know anything about Jackson, you know this is just as likely.
Historically Speaking 