On the morning of the 21st, at about eight o’clock, Colonel Canby ordered Colonel Roberts, with his cavalry, Colonel Valdez’s cavalry, Colonel Carson’s volunteers, the regular infantry, and Captain McRae’s and Lieutenant Hall’s batteries to proceed up the west bank of the Rio Grande, and prevent the Texans from reaching the water, at the only point where the river was fordable by the sloping banks. This position was seven miles north of the fort, and when Colonel Roberts’ command reached it, he found that the enemy had gained the water first. Colonel Roberts immediately opened his batteries upon them, on which they retreated with a loss of twenty-five or thirty killed, and one cannon. The gun was dismounted, spiked, and rendered unfit for use. Colonel Roberts then crossed the river, and held his position until the issue of the battle was decided. After one o’clock Colonel Canby came upon the ground with his staff, followed by Colonel Pino’s regiment of volunteers, and took the command in person. Up to this time the fighting had been principally with the batteries. Captain McRae’s battery occupied the left, and Lieutenant Hall’s battery the right of the line. On the left flank, and within about a hundred yards of McRae’s battery, was a piece of woods, where bodies of the enemy were seen to collect, but out of range of the guns. Two companies of regulars and two companies of volunteers were assigned to support this battery. Lieutenant Hall’s guns were to be supported by the cavalry and Colonel Carson’s volunteers. Thus disposed, Colonel Canby intended to make an advance, when suddenly a brisk fire of musketry was opened towards the right of the field. This was entirely unexpected, but the object was soon discovered to be a ruse to divert attention from an attempt which was immediately made to take the batteries. Advancing to the front, in two divisions, the enemy rushed on and made their charges against the batteries in the most determined and gallant manner. The charge against Lieutenant Hall’s battery was made by the cavalry, who dashed forward with an unbroken front, in the face of the destructive fire to which they were exposed. Standing true to their posts, the experienced gunners worked their pieces with such deadly effect, that the enemy was appalled by the carnage, and compelled to retire from the field.