'Texas Chainsaw' Facts

There seems to be a lot of conflict as to the truth of The Texas Chainsaw Massacre. I was just wondering if you could provide me any insight on the subject. Your archives don't go back to 1973 online. The movie says it was based on a true story, but several Web sites dispute the story and say it is not true at all. I would greatly appreciate any info you may be able to provide me so I can settle some local disputes with friends and co-workers.

   [Ed note: As far as we know the "true story" refers to Ed Gein in the Midwest upon whose exploits the original was loosely based. Readers?]