According to Boatner's Civil War Dictionary, the "original" Iron Brigade
was the one commanded by JP Hatch, consisting of the 2nd US Sharpshooters,
and the 22nd, 24th, 30th, and 84th NY. This brigade ceased to exist in
May of 63 when the 22, 24, and 30 NY were mustered out. I'm not
certain, but I think the 84th NY was the regiment also known as the
14th Brooklyn.
Jim Epperson
epperson@math.uah.edu