Northern Mexico had the greatest concentration of mineral resources as well as closest proximity to a major market for foodstuffs, the United States. As the railroad system improved, and as the population grew in the western U.S., large-scale commercial agriculture became viable. From the colonial period onward, the North had developed huge landed estates devoted mainly to cattle ranching. With the expansion of the rail network northward and with the Mexican government's policies of surveying land and clearing land titles, commercial agriculture expanded enormously, especially along the U.S.-Mexico border. Both U.S. and Mexican entrepreneurs began investing heavily in modernized large-scale agricultural estates along the railroad lines of the north. The family of future Mexican president Francisco I. Madero developed successful enterprises in the Comarca Lagunera region, which spans the states of Coahuila and Durango, where cotton was commercially grown. Madero sought to interest fellow large landowners in the region in pushing for the construction of a high dam to control periodic flooding along the Nazas river, and increase agricultural production there. One was constructed in the post-revolutionary period. The bilingual son of a U.S. immigrant to Mexico and the niece of the powerful Creel-Terrazas family of Chihuahua, Enrique Creel became a banker and intermediary between foreign investors and the Mexican government. As a powerful politician and landowner, Creel "became one of the most hated symbols of the Porfirian regime."