“. There are descriptions of extensive forests in the East with huge trees 6 and more feet in diameter,”
Those large trees were American Chestnut trees and they were still very common as late as 1900, after which the chestnut blight eliminated virtually every one of them.
Beeches grow really large too. There is one in Dumbarton Oaks in DC. Also I saw them in a museum display of the American Indidans. Also elms and mighty oaks. Incidentally, if you Google it you can find places to buy resistant American Chestnut trees to restock our forest lands. I’m thinking of getting some.
Forgot to mention there was also a very large old black walnut on the land where I spent my childhood living in an old Dutch colonial home. The oldest part was built in the late 1700s. I’m sure this tree was already mature then. It was at least 5 feet wide at waist height. I visited a few years ago and it and all the other smaller black walnuts on the property had been cut down and sold for timber. Grrrrrrrr!!!!!