More noble savage, whites killed and slaughtered them all...

Reading the blogs yesterday I came across a comment by someone who said that early US settlers killed millions of American Indians when they came to the US.

He stated that the population of indians in the US was something like 50-100 million

I'm just watching a recorded program which mentions the industrial revolution in Britain and the statement was made that the population had doubled to 21 million... could I just state that I had an indication from my bullshit meter that there couldn't be that many indians in the US... not without the facilities they had in the UK.

Youll find the comments, and some refutations, on this thread.