wow, well that's news to me. Very neat.Massad Ayoob says:
The [Mexican Carry] term is not perjorative. It arose long ago among gun people. In homage to proud Mexican men of the 19th and early 20th centuries. Beset by trants who stripped them of liberties, including the right to carry guns if they were not part of the political elite, these defiant citizens.... needed to be able to ditch the gun to be retrieved later if they were about to have contact with Federales, and since a holster could not be so quickly ditched and would be prima facie evidence of resistance to tyrants' law, the holster was dispensed with.
- The Gun Digest Book of Concealed Carry