Looks like Tsuga caroliniana to me as well. East TN is on the fringe of its native range.

tj

Awesome. They're actually in my grandfather's yard. He suspects they were about 5-10 when he moved in, which puts them being planted around 1965. The two tallest are probably about 60-70' and in good health considering how prevalent the adelgid is around here. I know it helps that they receive full sun though.

It's sometimes hard to distinguish between the two. The most obvious difference are the disordered needles in caroliniana, & more orderly/layered ones in canadensis. However, I've seen what I'm positive are canadensis w/somewhat disordered needles. Also, the form of older trees are different -- more open & irregular for caroliniana.

Carolina hemlock produces bigger cones. Since cones are present in this instance it should be possible to tell using those.

Simple Foliage Key to the Hemlocks and Spruces

http://arnoldia.arboretum.harvard.edu/pdf/articles/1943-3--simple-foliage-key-to-the-hemlocks-and-spruces.pdf

Thanks for that link, Embothrium.