One of your correspondents asked if the US Army’s Rifle Regiment had fought units from the Royal Army’s Rifles during the War of 1812. My quick answer would be, “not intentionally”. A more detailed answer is in a paper, about the 1st, 2nd, and almost mythical 3rd and 4th US Rifles: http://warof1812.ohio.gov/_assets/docs/rifles.pdf
Conclusion: The US Rifle Regiment was parceled out in one or two-company groups, often attached to Regular Army line regiments. The US Rifles were intended as skirmishers against Indian tribes east of the Mississippi. In fact, before 1812, most of the Regular Army trained for the skirmish-line since that was how they fought Indians. It took serious training to turn skirmishers into battle-line troops.
The only notable use of rifles, by either side, came during the British attempt to capture Baltimore, MD, in September, 1814. The British raiding division was commanded by a Major General Ross, who had won a battle at Bladensburg, MD, at the edge of DC, when Maryland and District of Columbia militia ran away. Ross then burned Washington, including the White House, the Capitol, and the Navy Yard; the raiders returned to their ships and landed near Baltimore. Warned that there might be 20,000 Maryland militia and 200 guns in a position prepared along a semi-circular ridge, Ross supposedly said “I don’t care if it rains militia”. A few minutes later, militia riflemen shot him.
John Welch