Dawn,
There were some very large Native Americans. A few years ago History Channel had a series Digging for the Truth, IIRC. Josh Bernstein examined some huge skeletons (but none over 7') in a museum in Terra del Fuego. In particular I remember one huge mandible that fit nicely over the outside of josh's jaw.

Then there is Lovelock Cave in Nevada [en.wikipedia.org]. The Paiute tribe has a legend of exterminating a band of red haired cannibalistic giants. You can see some of the huge skulls from Lovelock cave here: [www.google.com]

"The Stone Age did not end for lack of stone, and the Oil Age will end long before the world runs out of oil"

-- Sheikh Zaki Yamani