Saw it at a Drive-In in Philly when it first came out! One of the scariest movies ever! Based on real events!
No, not really. They stretched the truth quite a bit on that one. It's very loosely based on Ed Gein, the Wisconsin killer/grave robber from the 50s. The only similarity, really, is that Ed collected body parts, like Leatherface. In fact, he only killed twice, toward the end of his run. Before that, he just dug up bodies for souvenirs. But no chainsaw, and not in Texas, that's all urban legend. Psycho is a lot closer to the real story.
Great movie nonetheless.