Texas Mounted Volunteers
Jack Hays was a Texas Ranger, Indian Fighter, led this Regiment in the
Mexican War, and became the first Sheriff of San Francisco.
From the official Texas Ranger site: http://www.texasranger.org/dispatch/1/Hays.htm
Another good site: http://members.tripod.com/~jack0204/gen/Heskew/jack_c_hays.htm
A little on the war, itself: http://www.texasmilitaryforcesmuseum.org/tnghist9.htm
And, something about the war itself: http://www.dmwv.org/mexwar/mexwar1.htm
and, a pretty good site: http://www.sonofthesouth.net/mexican-war/war.htm