The town's name came from one of the first conductors, W. T. Colmesneil, on the
Texas and New Orleans Railroad, which ran through the county. The Trinity and Sabine Railroad extended a 66-mile line from Colmesneil to
Trinity, establishing the town as the shipping focal point for the county from 1881.
Timber and cattle were the foremost commodities to sell due to the steep slope of the terrain. From the 1880s, the Yellow Pine Lumber Company operated a mill there, and for a while, Colmesneil's population was greater than that of
Beaumont. The surname
Colmesneil is probably a misspelling for
Colmesnil, a
Norman surname originally designating "someone from
Colmesnil", a village in the traditional
pays de Caux district, in département
Seine-Maritime, Normandy, France. It means "
Koli′s rural estate",
Koli being the name of a Scandinavian settler (see
Colleville). ==Geography==