Pakenham, as adjutant-general, joined his well-known in-law, the Duke of Wellington, in the Peninsular War. He commanded a regiment in the Battle of Bussaco in 1810 and in 1811 fought in the Battle of Fuentes de Onoro to defend the besieged fortress of Almeida, helping to secure a British victory. In 1812 he was praised for his performance at Salamanca in which he commanded the Third Division and hammered onto the flank of the extended French line. He also received the Army Gold Cross and clasps for the battles of Martinique, Busaco, Fuentes de Oñoro, Salamanca, Pyrenees, Nivelle, Nive, Orthez, and Toulouse.
In September 1814, Pakenham, having been promoted to the rank of major general, accepted an offer to replace General Robert Ross as commander of the British North American army, after Ross was killed during the skirmishing prior to the Battle of North Point near Baltimore. The next year during the Battle of New Orleans while rallying his troops near the enemy line, grapeshot from US artillery shattered his left knee and killed his horse. As he was helped to his feet by his senior aide-de-camp, Major Duncan MacDougall, Pakenham was wounded a second time in his right arm. After he mounted MacDougall's horse, more grapeshot ripped through his spine, fatally wounding him, and he was carried off the battlefield on a stretcher. He was laid beneath the oaks which today still bear his name. He was 36. His last words were reputed to be telling MacDougall to find General John Lambert to tell him to assume command as well as "Tell him... tell Lambert to send forward the reserves." The battle ended in defeat for the British. The American commander was Brevet Major General Andrew Jackson, who would go on to become the seventhPresident of the United States from 1829 to 1837. A general ceasefire had already been declared by the Treaty of Ghent, signed on 24 December 1814, but as peace was not yet ratified in Washington as required by the treaty, the two nations were still formally at war. The news of the treaty did not reach the combatants until February, several weeks after the battle. Wellington had held Pakenham in high regard and was deeply saddened by news of his death, commenting:
We have but one consolation, that he fell as he lived, in the honourable discharge of his duty and distinguished as a soldier and a man. I cannot but regret that he was ever employed on such a service or with such a colleague. The expedition to New Orleans originated with that colleague... The Americans were prepared with an army in a fortified position which still would have been carried, if the duties of others, that is of the Admiral, had been as well performed as that of he whom we now lament.
Legacy
There is a statue in his memory at the South Transept of St Paul's Cathedral in London. His body was returned in a cask of rum and buried in the Pakenham family vault in Killucan in County Westmeath, Ireland. The village of Pakenham in Ontario, Canada, named in honour of the general's short visit there and his role in the War of 1812. The village is located on the Mississippi River which originates from Mississippi Lake and empties into the Ottawa River. There is also a suburb of Melbourne, Australia, named after him. In the alternative "British Version" of Johnny Horton's novelty hit "The Battle of New Orleans," Horton refers to the British being led into battle by Pakenham. As with other 'historic' details of the song, Horton haphazardly styles him as "Colonel Pakeningham" despite his actually being General Pakenham.
