I understand that they were a Royal Green Jacket Rifles Regiment akin to the 95th and 60th Rifles. I know what the Rifles were for and how they were used. The question I have is who were the "American Rifles" in the early 19th century. I cannot remember what I was reading, but it took place in northern Portugal during the Peninsula War and I want to say it may specifically have been the Second Battle of Porto when Wellesley routed Soult. I saw a passing mention to the American Rifles and was wondering where exactly they were recruited from if this was a post-American Revolution world.
I apologize for how wordy this comment/question is but I was just trying to be specific. Thanks historians.
They were the 60th Rifles - The rifle battalions serving in the Peninsular came from three different units. These were the 95th (Rifles) Regiment, the King's German Legion, and the 60th (Royal American) Regiment. The 60th Regiment had been raised in the American colonies in 1755, as the 62nd Regiment. It was renumbered to the 60th the following year. The regiment was not composed solely of American colonists, but also of Swiss and German expats, and British volunteers. Most of the officers were British. The regiment saw sterling service in the 7 Years War and Pontiac's Rebellion. They also operated in the American Revolutionary War. Post-American Revolution, the unit retained it's name, the Royal American Regiment, but no longer included American colonists, for obvious reasons. Instead, the numbers were made up by German and Swiss expats. For example, after Vimeiro, the 5th Battalion received 200 Swiss troops, who had defected from French forces.
Sources:
Charles Esdaile, The Peninsular War, Macmillan, 2003
Nesbit Wallace, A Regimental Chronicle and List of Officers of the 60th or Kings Royal Rifle Corps, formerly the 62nd or the Royal American Regiment of Foot, Harrison, 1879, available at https://archive.org/stream/regimentalchroni00walluoft#page/n9/mode/2up