Why did andrew jackson fight a battle after he war was over

In September 1814, an impressive American naval victory on Lake Champlain forced invading British forces back into Canada and led to the conclusion of peace negotiations in Ghent, Belgium. Although the peace agreement was signed on December 24, word did not reach the British forces assailing the Gulf coast in time to halt a major attack.On January 8, 1815, the British marched against New Orleans, hoping that by capturing the city they could separate Louisiana from the rest of the United States. Pirate Jean Lafitte, however, had warned the Americans of the attack, and the arriving British found militiamen under General Andrew Jackson strongly entrenched at the Rodriquez Canal. In two separate assaults, the 7,500 British soldiers under Sir Edward Pakenham were unable to penetrate the U.S. defenses, and Jackson’s 4,500 troops, many of them expert marksmen from Kentucky and Tennessee, decimated the British lines. In half an hour, the British had retreated, General Pakenham was dead, and nearly 2,000 of his men were killed, wounded, or missing. U.S. forces suffered only eight killed and 13 wounded.Although the battle had no bearing on the outcome of the war, Jackson’s overwhelming victory elevated national pride, which had suffered a number of setbacks during the War of 1812. The Battle of New Orleans was also the last armed engagement between the United States and Britain.

That really sucks, but i don't know who your leader is, and i don't want to write that much