I always find W. Thomas Smith, Jr.'s "This Week In American Military History" series to be an interesting read. This week's edition references the Battle of New Orleans, which took place over two weeks after the Treaty of Ghent was signed on Christmas Eve in Europe, ending the War of 1812 (in 1815).
Without satellite communication or Facebook, news that the war had ended did not reach New Orleans until February.
In the battle, which lasted over two weeks, General Andrew Jackson defeated a numerically superior British force. The British abandoned Louisiana for the Mobile Bay and were preparing to strike Mobile, Ala. when news of the treaty reached them.