Southward the altitude falls, Death valley and Coahuila valley being in part below the level of the sea.
Stock-raising was for a time the principal industry, but agriculture has been largely developed in several localities, among the chief products of which are cotton - Coahuila is the principal cotton-producing state in Mexico - Indian corn, wheat, beans, sugar and grapes.
The first Spanish settlement in the region now called Coahuila was at Saltillo in 1586, when it formed part of the province of Nueva Viscaya.
Later it became the province of Nueva Estremadura under the Spanish regime, and in 1824, under the new republican organization, it became the state of Coahuila and included Texas and Nuevo Leon.
The general character of the surface is mountainous, though the western and south-western sides are level and dry as in the adjoining state of Coahuila.