Don Pelagio Sandoval, not wishing to leave any enemy in his rear, suddenly attacked the Presidio of the Río Grande as well as the forts of the Agua Verde and Bahia, built on the Río del Norte, in order to protect the border against Indian forays, and after a vigorous resistance, carried them by storm. The insurgent general, in order not to embarrass his army with prisoners, contented himself with disarming the Spanish garrisons, and left them free to retire wherever they pleased. This merciful policy formed too great a contrast with the rigorous system hitherto adopted by the government, not to produce a good result, whose effect was immediately felt; many officers and soldiers, natives of New Spain, offered their swords to the insurrection, and passed into the ranks of the Mexican army. One town alone still resisted the general movement and remained faithful to Spain; this town was Coahuila. General Don López de Cárdenas, at the first insurrectionary movement, called in all the Spanish garrisons scattered through the other towns, which he despaired of defending effectually against the formidable forces of the insurgents, and shut himself up in Coahuila, resolved to bury himself beneath the smoking ashes sooner than open the gates to men whom he regarded as miserable rebels, deceived and seduced by a fanatic priest. After proclaiming independence in all the towns of the province, and establishing the national government, Don Pelagio led on Coahuila the forces at his disposal, which, as we said, had been largely augmented by the contingents constantly supplied by the liberals, and now rose to the really formidable number of 25,000 men. The Mexicans reached the town after meeting with no further obstacle than a considerable cavalry corps, probably sent to reconnoitre, and which, after exchanging a few carbine shots with the vanguard, declined a contest and fell back. The town was immediately invested. General Cárdenas was not only an old soldier, but also a skilful strategist; in the prevision of a revolt, he had abundance of arms and ammunition at Coahuila, and so soon as he was shut up in the town, he had earth breastworks thrown up, and wide ditches dug. Hence a regular siege was about to begin against an enemy who was too well aware of the hatred he had aroused not to offer a vigorous resistance. The priest's first care was to trace a parallel, and throw up entrenchments. The flag of independence was haughtily hoisted on the jacal, which served as headquarters, and Don Pelagio summoned the town to surrender. On hearing the Mexican bugles, General Cárdenas appeared on the ramparts, surrounded by a large party of Spanish officers, smart as gold lace could make them. "Who are you and what do you want?" he said in a haughty voice, addressing the officer who commanded the Spanish detachment.