Here's the trailer for the re-release (maybe NSFW)
Writer John Bloom, aka Joe Bob Briggs, authored a terrific history of the making of the movie in this 2004 essay, go read it. Bloom keenly observes:
"Chainsaw was the first baby-boomer horror film, in which pampered but idealistic suburban children, distrustful of anyone over thirty, are terrorized by the deformed adult world that dwells on the grungy side of the railroad tracks. There had been other films that treated rural America as a place of seething, barely contained violence—notably Deliverance—but never one in which the distinction was so clearly made between an old America, of twisted, deranged adults, and a new America, of honest, right-thinking children."
And there's this:
"We had no prop man, so I found the props. We didn’t even have a chain saw. I found one. Of course, today I would know that if you’re making a movie with ‘chain saw’ in the title, you should have ten, not just one. But we had one. A McCollough. I had to take the teeth out of it so it wouldn’t hurt anyone. I remember we wrote a letter to McCollough, thinking they might want to invest in the movie. They never answered us.”
Bloom details the movie's connection to a wee baby Gwyneth Paltrow, director Sidney Lumet, and the resignation of President Nixon. Bloom of course is a horror/drive-in legend for his Joe Bob writings, and was even given a cameo in the 1986 sequel, the movie which also gave us Bill Mosely as Chop-Top and Dennis Hopper in all his bizarro glory as a Texas Ranger hunting down the cannibal family. But this sequel is more of a mash-up of Looney Tunes and Chainsaws.
The original is a take-no-prisoners descent into madness.
Director/writer Tobe Hooper did such a good job scaring the crap out of audiences and Hollywood, his career never really took off, despite his success with "Poltergeist". And oddly the formula he created for the independent (now mainstream) horror movie was copied and repeated to bring massive success to John Carpenter and Sam Raimi. But Hooper, the first to break thru so many barriers, was a casualty.