I know this thread is very old, but here's a story about one of my wife's ancestors that helps fill out some information about the 72nd:
Walter Ferguson of Old Cumnock, Ayrshire:
Walter joined the Lord Elgin Fencibles on 1 November 1799 at Cumnock in Ayrshire and became a private in 72nd Regiment of Foot on 4 July 1800 at Newry, County Down, Ireland. The fencibles were local militia who were recruited for home service, but not overseas service. These Highland militia groups were generally disbanded around 1799, and the Lord Elgin Fencibles were mostly recruited into the 72nd. Walter enlisted while aged 24 and was discharged with the rank of serjeant (the way foot regiments spelled ‘sergeant’) on 9 November 1819 when he was closer to 46 than the 43 recorded on his service record.
Walter’s wife, Anne Phillips (born in Cork, Ireland), also travelled with the regiment throughout his service. While we have no record of their marriage, it is likely they married while he was on active service in Ireland with the regiment in 1798–1806. While in Ireland, his first four children were born: Catherine in 1798/9; James in 1800/1; Margaret 1801/2; and Elizabeth 1803/4 – all of these died at two years or younger.
Walter and Anne went with the regiment when it captured the Cape of Good Hope (South Africa) from the Dutch in 1806. It was during this campaign that his first two children to survive to adulthood were born: Janet in 1806, and William in 1808 (Janet died in 1829 in Cumnock aged 23). Walter was made corporal on Christmas Day 1807, but was further promoted to serjeant on 25 June 1809.
The 72nd was next in action against the French during the Napoleonic Wars. The regiment helped capture Mauritius (Île de France) in November 1810, and the 72nd remained on as garrison troops in Port Louis until around June 1814. We know that his children Catherine (1811) and Walter (1815) were both born in Mauritius. The army registered this as service in the East Indies.
The regiment was known to have moved to Calcutta, India in 1815, and this is probably where he was during the period September 1815 and February 1816. His whereabouts from June 1814 to September 1815 are unknown, but the 72nd had returned to the Cape of Good Hope by 1816 as part of the Cape Province Garrison, and was soon involved in the Kaffir Wars of 1818–1819. During this period, his daughter Elizabeth (1816) and last child Thomas (1818) were born.
Walter, whose service was described as “very good”, was discharged from the army on 9 November 1819 after becoming a “supernumerary”. He incurred a disabling injury to his right hand while working with the Engineers. He returned to Cumnock in Ayrshire – along with Anne, Janet, William, Walter, Elizabeth and Thomas. Walter had 20 years service with the 72nd and, with his injury on duty, he was entitled to an army stipend as a Chelsea Out-Pensioner.