"Iced Earth" is mostly likely the United States biggest contribution to traditional Metal in the past couple decades.

The Roots of the band go way back to 1985 with guitarist/song-writer John Schaffer.  He IS "Iced Earth" for all intensive purposes.  They have a massive library of albums that have been critically acclaimed around the world.  Their fan-base also spans world-wide as well. If there was ever an American version of Iron Maiden, this would bit it.

They have had five lead singer, including former Judas Priest frontman Ripper Owens.  Matt Barlow was the most well-known as he was there through their rise in the Metal ranks.  Canadian Stu Block recently took over the vocal duties for the band, here's their 2011 release "Dystopia".