COAHUILA  , a

northern frontier state of Mexico, bounded N. and N.E. by Texas, U.S.A., E. by Nuevo Leon, S. by San Luis Potosi and Zacatecas, and W. by Durango and Chihuahua . Area, 63,569 sq. m.; pop . (1895) 237,$15; (1900) 296,938 . Its surface is a roughly broken plateau, traversed N.W. to S.E. by several ranges of mountains and sloping gently toward the Rio Grande . The only level tract of any size in the state is the Bolson de Mapimf, a great depression on the western side which was long considered barren and uninhabitable . It is a region of lakes and morasses, of arid plains and high temperatures, but experiments with irrigation toward the end of the 19th century were highly successful and considerable tracts have since been brought under cultivation . In general the state is insufficiently watered, the rainfall being light and the rivers small . The rivers flow eastward to the Rio Grande . The climate is hot and dry, and generally healthy . 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 Parras district in the southern part of the state has long been celebrated for its wines and brandies . The mineral wealth of the state is very great, and the mining industries, largely operated with foreign capital, are important .

The mineral products include

silver, lead, coal, copper, and iron . The mining operations are chiefly centred in the Sierra Mojada, Sierra Carmen, and in the Santa Rosa valley . The modern industrial development of the state is due to the railway lines constructed across it during the last quarter of the 19th century, and to the investment of foreign capital in local enterprises . 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 . Later in the same year Nuevo Leon was detached, but Texas remained a part of the state until 1835 . The capital of the state is Saltillo; Monclova was the capital from 1833 to 1835 . Among the more important towns are Parras (pop . 6476 in 1900), 98 m . W. by N. of Saltillo in a rich grape-producing district, Ciudad Porfirio Diaz, and Monclova (pop . 6684 in 1900), 105 m . N. by W. of Saltillo, on the Mexican International railway .