Negotiations between the United Kingdom and the United States to end the War of 1812 began in Ghent in late August 1814. A peace treaty was signed on 24 December and ratified by the British government three days later. However, the slow speed of communications in those days meant that it took some time until the news reached the USA. Fighting therefore continued for nearly two months.
In December 1814 10,000 British troops landed near New Orleans. They were commanded by Sir Edward Pakenham, like most of his men a veteran of the Peninsular War. The advance guard under Major General John Keane camped nine miles from New Orleans at noon on 23 December. By the early evening his initial 1,900 men had been joined by another 400.
Andrew Jackson, who had been in command of the defences for only three weeks, decided to strike the first blow. He attacked Keane with a force of just over 2,000 after dark on 23 December. The British troops were more experienced as well as more numerous. They could possibly claim a tactical victory as they held their ground, albeit at the expense of nearly 300 casualties versus over 200 American. The latter withdrew three miles.
However, the action was a strategic success for the Americans, who halted the British advance for long enough to erect a series of breastworks, defended by 3,000 men, with their flank protected by the corvette USS Louisiana in the Mississippi.
Pakenham advanced to the breastwork on Christmas Day. He then halted for three days, before launching a series of probing assaults. Heavy British guns were brought up, with the intention of attacking on 1 January. However, the Americans had the better of the pre-attack artillery duel, so Pakenham cancelled the assault.
The next attack was to take place on 8 January. A canal would be dug to take 1,500 men under Colonel William Thornton to the Mississippi in ship’s boats. They would then cross the river and assault a redoubt that had been established on the west bank with three 24 pounders and six 12 pounders, which could fire into the flank of the attack by the other 8,500 men on the east bank.
The official US returns stated that there were initially 4,698 men on the east bank and 546 on the west. Another 500 men were ordered by Jackson the reinforce the latter, but 100 did not arrive in time and only 250 of the others were armed. This gives a total of 5,494 Americans at the battle, but Theodore Roosevelt notes that there may be a double counting of the 500 sent to the west bank, reducing Jackson’s force to about 5,000.
The sounds of the British preparation alerted Jackson the impending assault, so his men were on the alert before dawn. The British attackers on the east bank were initially protected by a fog, but it lifted when they were 400 yards from the American defences.
The sides of the canal that was intended to take Thornton’s force to the river caved in, with the result that it was late in setting off and only 700 men crossed. They landed in the wrong place, but were able to take their objective. Jackson organised a counter attack, but the British withdrew before it went in as Colonel Alexander Dickson, the British artillery commander, estimated that 2,000 men would be needed to hold the position.
By then, the main British attack had been repulsed with heavy casualties. Pakenham, his second in command Major General Sir Samuel Gibbs being killed. Keane was wounded, leaving Major General Sir John Lambert, the only uninjured British general present, in command. Gibbs, Keane and Lambert had all been knighted on 2 January. Wikipedia gives British casualties as being 2,042: 291 killed, 1,267 wounded and 484 captured or missing. American ones were 71: 13 dead, 39 wounded and 19 missing.
The two armies then faced each other for 10 days. The position was too strong for the British to take, especially as Jackson was receiving reinforcements. However, he was unwilling to attack, since the British troops were more experienced than the Americans, so would have an advantage fighting in the open.
Lambert retreated his force on 18 January. It re-embarked on its transport ships and headed for Mobile. On 8 February 1,500 men were landed at Fort Boyer, which surrendered with the honours of wars on 12 February, a few hours before the news of the end of the war arrived. Casualties were 11 Americans and 31 British.
New Orleans was a major US victory that saved the city and Louisiana from being devastated. As Americans learnt of it before they heard about the end of the war, it was natural for them to assume that it won them the war. However, this was not the case as peace terms had already been agreed. Jackson, the architect of the victory, was rightly regarded as the best American general of the war and later became President.
 Troop numbers and casualties are from T. Roosevelt, The Naval War of 1812, 2 vols. (New York, NY: Charles Scribner’s Sons, 1900-2). vol. ii, pp. 211-68
 Ibid., p. 238. Note 2.