There is no such thing as the Texas Chainsaw Murders. Despite the disclaimer at the beginning of the original film, which touts the movie as "...an account of a tragedy which befell a group of five youths...For them an idyllic summer afternoon drive became a nightmare...This video cassette is based on a true incident and is definitely not for the squeamish..." in truth The Texas Chainsaw Massacre was not really based on a true story.
The filmmakers just wanted people to think it was a true story, so more people would go see the movie. It was also a bit of a joke on their part, to see if people would believe it was real. This is not an unheard-of tactic: for example, the Blair Witch Project was also touted as a true story by the filmmakers, when in truth it is completely fictional and all the actors in it are alive and well to this day.
The Texas Chainsaw Massacre was inspired by a true story, which is a long way away from being based on a true story. The truth is that the director, Tobe Hooper, got the idea for the Leatherface character from the real case of the serial killer Ed Gein. The rest is completely fictional. Ed Gein was only one man; he did not belong to a family of chainsaw murderers, and he lived in Wisconsin, not Texas.
Ed Gein murdered at least two women, one of whom was found hanging disemboweled and decapitated in his house, and also allegedly engaged in necrophilia and cannibalism with his victims' corpses. He did not, however, murder them with a chainsaw.
I have included a link to the snopes.com page about the Texas Chainsaw Massacre. I have also included a link to a page that compares the Ed Gein murders to the movie.
The cast of South Texas Chainsaw Murders - 2013 includes: Julio Leal as Hector Sanchez Robyn Von Arx as Melanie Sanchez
The cast of Chainsaw Scumfuck - 1988 includes: Ollie Bond Alex Chandon Matt Russel
The cast of The Russian Newspaper Murders - 2004 includes: Leslie Woodhead as Narrator
The cast of Murders Inn - 2009 includes: Hayley Derryberry as Grace Englund Rich Henrich as Norman
The cast of Slash Hive - 2007 includes: Simon Meacock as Chainsaw Victim
The cast of The Helsinki Axe Murders - 2008 includes: Zoe Chandler as Susan Salter Tero Salenius as Man at the police station
The cast of American Chainsaw - 2012 includes: Scarlett Bruns as Mandy
The cast of The Resort Murders - 1998 includes: Zoren Legaspi
The cast of The Chelsea Murders - 1981 includes: Penny Leatherbarrow as Barmaid
The cast of The Bellevue Murders - 2014 includes: Andrea Kelley as Brynn
The cast of Chainsaw Scumfuck - 1988 includes: Ollie Bond Alex Chandon Matt Russel
The cast of Honeymoon Murders - 1990 includes: Dave Knapp Angela Shepard
The cast of ABC Murders - 2009 includes: JB Blanc Tara Platt
The cast of The Tarmak Murders - 1978 includes: George Marshall Ruge as Demeter
The cast of The Russian Newspaper Murders - 2004 includes: Leslie Woodhead as Narrator
The cast of Chainsaw Ballet - 2011 includes: Neil Cadger Nikki Cormaci Lara Haworth Gabriel Newman
The cast of Honeymoon Murders II - 1990 includes: Tom Eckert Donna Kozlowski
The cast of The Electric Chainsaw Massacre - 2009 includes: Todd Ryan Jones as Pleatherface Rebekah Wendell as The Girl