At the point where the army struck the Little Colorado River, the stream was quite wide and of sufficient depth for navigation. The water was brackish and the banks were fringed with timber. Here the whole army concentrated before attempting to cross. The army was not accompanied by a pontoon train, and at that time the troops were not instructed in bridge building. To add to the embarrassment of the situation, the army was here, for the first time, threatened with opposition.
Buglers, concealed from our view by the brush on the opposite side, sounded the "assembly," and other military calls. Like the wolves before spoken of, they gave the impression that there was a large number of them and that, if the troops were in proportion to the noise, they were sufficient to devour General Taylor and his army. There were probably but few troops, and those engaged principally in watching the movements of the "invader." A few of our cavalry dashed in, and forded and swam the stream, and all opposition was soon dispersed. I do not remember that a single shot was fired.
The troops waded the stream, which was up to their necks in the deepest part. Teams were crossed by attaching a long rope to the end of the wagon tongue passing it between the two swing mules and by the side of the leader, hitching his bridle as well as the bridle of the mules in rear to it, and carrying the end to men on the opposite shore. The bank down to the water was steep on both sides. A rope long enough to cross the river, therefore, was attached to the back axle of the wagon, and men behind would hold the rope to prevent the wagon "beating" the mules into the water. This latter rope also served the purpose of bringing the end of the forward one back, to be used over again. The water was deep enough for a short distance to swim the little Mexican mules which the army was then using, but they, and the wagons, were pulled through so fast by the men at the end of the rope ahead, that no time was left them to show their obstinacy. In this manner the artillery and transportation of the "army of occupation" crossed the Colorado River.
About the middle of the month of March the advance of the army reached the Rio Grande and went into camp near the banks of the river, opposite the city of Matamoras and almost under the guns of a small fort at the lower end of the town. There was not at that time a single habitation from Corpus Christi until the Rio Grande was reached.
The work of fortifying was commenced at once. The fort was laid out by the engineers, but the work was done by the soldiers under the supervision of their officers, the chief engineer retaining general directions. The Mexicans now became so incensed at our near approach that some of their troops crossed the river above us, and made it unsafe for small bodies of men to go far beyond the limits of camp. They captured two companies of dragoons, commanded by Captains Thornton and Hardee. The latter figured as a general in the late war, on the Confederate side, and was author of the tactics first used by both armies. Lieutenant Theodric Porter, of the 4th infantry, was killed while out with a small detachment; and Major Cross, the assistant quartermaster-general, had also been killed not far from camp.
There was no base of supplies nearer than Point Isabel, on the coast, north of the mouth of the Rio Grande and twenty-five miles away. The enemy, if the Mexicans could be called such at this time when no war had been declared, hovered about in such numbers that it was not safe to send a wagon train after supplies with any escort that could be spared. I have already said that General Taylor's whole command on the Rio Grande numbered less than three thousand men. He had, however, a few more troops at Point Isabel or Brazos Santiago. The supplies brought from Corpus Christi in wagons were running short. Work was therefore pushed with great vigor on the defences, to enable the minimum number of troops to hold the fort. All the men who could be employed, were kept at work from early dawn until darkness closed the labors of the day. With all this the fort was not completed until the supplies grew so short that further delay in obtaining more could not be thought of. By the latter part of April the work was in a partially defensible condition, and the 7th infantry, Major Jacob Brown commanding, was marched in to garrison it, with some few pieces of artillery. All the supplies on hand, with the exception of enough to carry the rest of the army to Point Isabel, were left with the garrison, and the march was commenced with the remainder of the command, every wagon being taken with the army. Early on the second day after starting the force reached its destination, without opposition from the Mexicans. There was some delay in getting supplies ashore from vessels at anchor in the open roadstead.