Factory/Dealer installed trailer hitch on a 1970 Dodge Dart?

Did Dodge Dart's ever come with trailer hitches? My 1970 Dart had one, I removed it but kept it. It bolted on behind the bumper on the brackets (had to pull bumper off to remove) It also had one support that bolted to the trunk floor in the spare tire area. Nice quality hitch, it is definetly made for this car and looked fine installed. Is this a factory option or dealer installed? I will get some pics up if there is any interest, Thanks!