In the spring of 1846, General Taylor of the regular army of the United States was sent to the mouth of the Rio Grande, or Rio Bravo del Norte, as it is also called, with a small force. Mexican troops also assembled there, and a conflict was precipitated by a Mexican ambuscade on the Texas side of the river, which attacked a small party of dragoons, reconnoitering. In this skirmish sixteen Americans were killed or wounded, and the whole force was captured. This was the beginning of hostilities. The Mexican army crossed the Rio Grande, and on the 8th of May the battle of Palo Alto was fought, and that of Resaca de la Palma on the next day. Both of these places are on the Texas side of the river. The Mexicans were defeated in each engagement, and they left the field with a better opinion of the capacity of American troops than the one they held before. The rout of the Mexicans was complete; their pieces of light artillery, their camp, and five hundred pack-mules and saddles remained in the hands of their enemies. General Arista, the commander of the Mexican force, lost his personal baggage, plate, and public correspondence. The number of killed and wounded was estimated at more than a thousand.

After this action, both parties crossed the river, and Mexico became the theatre of warfare. The Mexican army withdrew at first to Matamoras, at the mouth of the Rio Grande, and afterward to San Luis de Potosi; Arista was deprived of his command, and brought to trial before a council of war.

This was the opening of the conflict, and this might well have been the end, if Mexico had been capable of rational negotiation. But there was no government long enough in place to be negotiated with. The special envoy sent from Washington, agreeably to an intimation on the part of one President, that negotiations would be cordially entered upon, was refused an audience by the new President who had usurped the place of the other one. Such weakness in Mexican high places furnished an excuse to the American government for continuing the war, while this same weakness on the part of their antagonist made it almost discreditable for the United States to continue an aggressive warfare upon forces so unequal.

However, the war was begun. Hostilities had been opened by Mexico, and the American people of all parties were aroused. Bills were promptly passed in Washington providing men, money, and munitions with alacrity, as if there were but one opinion of the justice of the cause. The President was authorized to call for volunteers, in any number not exceeding fifty thousand, to serve for the period of one year, or during the war, and volunteers readily answered the appeal to arms.

"Indemnity for the past and security for the future," is the watchword of the United States in its wars with foreign nations. As indemnity for the wrongs inflicted by Mexico,—that is, her objection to the admission of Texas to the Union, it was determined to cross her boundary line and seize upon her territory.

California, then sparsely settled, and comparatively unknown, at a long distance from the central and civilized part of Mexico, had been explored already by American travellers, who brought back accounts of its climate, fertile soil, and mineral resources that showed it to be worth having. The harbors on its coasts were known to be the only good ones on the shores of the Northern Pacific Ocean. California lay immediately south of the United States territory of Oregon, with no defined natural boundary between them. Many Americans were already settled there, and altogether it seemed well to transfer this goodly region to the keeping of the United States. New Mexico, another department of the Mexican Republic, lying upon the direct route to California, and in great part included in the boundaries claimed by Texas upon her admission to the Union, was also another territory that claimed attention.

It would be too much to say that the United States began hostilities with a neighboring republic, shaken by internal discord, its government little better than anarchy, and weak from continuous civil war, for the sake of snatching from that country a large part of its territory to enlarge its own already wide proportions. But since the Mexicans, foolishly and wickedly, had given fair pretext for quarrel, and afterwards, with the obstinacy of naughty children, refused to recede, and persisted in resorting to arms, actually making the first attack, it seemed well to the United States government to call this the inevitable, and accept it with all the benefits arising from such a course.

Their general plan of operations was to seize and occupy the coveted territories as "indemnity for the expenses of war," while an army invading the heart of Mexico should force an agreement to terms of peace.

In pursuance of this plan, an American squadron appeared before the fort of Monterey, on the Pacific, in Alta California, on the 7th of July, two months after the first shots of warfare on the Rio Grande. This Monterey must not be confounded with the other Mexican town of the same name. The Mexicans evacuated the place with the few soldiers who constituted the garrison. On the same day two hundred and fifty seamen landed, and took possession, and hoisted the American flag. This course was in pursuance of instructions from the Secretary of the Navy to the commander of the Pacific squadron, thus expressed in a letter, written as early as June 24, 1845: "It is the earnest desire of the President to pursue the policy of peace, and he is anxious that you, and every part of your squadron, should be assiduously careful to avoid any act which could be construed into an act of aggression. Should Mexico, however, be resolutely bent on hostilities, you will be mindful to protect the persons and interests of citizens of the United States, and should you ascertain beyond a doubt that the Mexican government has declared war against us, you will employ the force under your command to the best advantage. The Mexican ports on the Pacific are said to be open and defenceless. If you ascertain with certainty that Mexico has declared war against the United States, you will at once blockade or occupy such ports as your force may admit."

Other ports were taken with equal ease; and the navy having joined forces with the army of Colonel Fremont, the Americans entered the capital of Alta California, on the 13th of August, and took possession of the government house without a show of opposition, issuing at once a proclamation announcing the conquest of the department.

Meanwhile General Taylor, greatly reinforced by volunteer troops sent from the United States, advanced into the interior of the country though the state of Nueva Leon, bordering upon the Rio Grande and the Gulf of Mexico, and approached its capital, the other Monterey. It lies at the eastern base of a range of hills, in a valley of great fertility, which is capable of supporting a large population. The main road from the Rio Grande to the city of Mexico leads from the east through a cultivated country, directly through the city, and continues by a pass through the Sierra, by Saltillo, and on to a desert region between Saltillo and San Luis de Potosi. A rivulet, the San Juan de Monterey, rises in this pass and crosses the valley. Monterey stands on the northern bank of this rivulet, and extends along the stream. At the time of the battle it contained about two thousand inhabitants. A spur of the mountain Sierra juts out above the city to the west, and on this is perched the picturesque Obispado Viejo, or Old Palace, built by a bishop of the last century for his pleasure-seat.

General Ampudia had the charge of the defence of the place, with over ten thousand men. The town was plentifully supplied with ammunition, and in the various batteries forty-two guns were mounted. Subsistence for some days, beef, cattle, and sheep, had been introduced into the city. The attacking force was known to be too small to completely invest the town.

The American army made a vigorous onslaught which was bravely resisted by the Mexicans. The siege lasted for four days, during which the position of the bishop's palace was keenly contested by both parties. This was stormed on the morning of the 22d, and carried by a brilliant attack; but the fate of the siege was not decided until the 25th, when the Mexican garrison evacuated the citadel, and retreated to Saltillo.

The force with which General Taylor had marched on Monterey was about six thousand five hundred men. The loss to the American army was twelve officers and one hundred and eight men killed, and thirty-one officers and three hundred and thirty-seven men wounded. The number of Mexicans who fell was probably over one thousand.

Both sides fought with great bravery, and the Mexicans contested the occupation of their town with determination, during the long and unceasing conflict. The result was terribly discouraging to the soldiers of the Mexican army, who were discovering, with every new essay, that the United States soldiers could fight.

General Ampudia, after the defeat, issued a proclamation announcing it frankly, with humble apologies for his capacity. He gave a short account of the operations, highly extolling the valor of his troops, and attributing the defeat to a series of accidents, concluding with the assurance to his countrymen that the loss of Monterey was of little importance, and would soon be forgotten in fresh triumphs of the Mexican arms.

He soon received orders to march his troops to San Luis de Potosi, on the backward way towards the capital.

The operations at Monterey, in spite of the opinion of the Mexican general, had nevertheless a great effect on the progress of the war. It must have been discouraging to the Mexican people; on the other hand, it made the war more popular in the United States, where the bravery of the troops was a subject of national congratulation.

The officers in the army of General Taylor became heroes, and their military glory was everywhere sounded.

During these events Don Maria Paredes was President of Mexico. His "Plan" for his country was a monarchy, and apparently heedless, or at any rate indifferent, to the approach of hostile troops toward his capital, he occupied himself with forming a ministry favorable to his scheme, with the intent of making sooner or later a radical change in the political institutions of the country.

Such intentions had aroused a violent opposition to his administration. Santa Anna, apparently amusing himself at Havana, but always well informed by his partisans of what was going on at home, sent home letters declaring himself in favor of the Constitution of 1824, and ready, as usual, to serve his country. The American government, hearing of this, thought it well to encourage Santa Anna, in opposition to Paredes, for they looked with no favor on the idea of a monarchy in Mexico, and moreover saw that all negotiations for peace were futile during the stay of Paredes in power. The Gulf of Mexico was already blockaded by an American squadron, but orders were issued to permit Santa Anna to come in, if he wanted to. This order was given before the battles of Palo Alto and Resaca de la Palma, and must be taken as a sign of willingness on the part of the United States for a pacific accommodation.

But Santa Anna's gifts were those of a military nature, not for peaceful solutions. If he was to serve his country, it must be by waving the battle flag and not the olive branch.

The defeats of the army reminded Paredes of the need of regaining his prestige. He began to put forth some energy in raising men and money, and gave out that he should repair to the field of action himself to conduct operations against the invaders in person. Raising money with great difficulty, and assembling a large army, he made ready to leave the capital on the 31st of July. On that day the garrison of Vera Cruz pronounced in favor of Santa Anna, the whole garrison of the city of Mexico joined in the pronunciamento and seized upon the citadel. FarÍas, whom we have known as a patriotic man, lent all his influence to support this rebellion. The Vice-President, Bravo, and the old ministry, made some opposition on paper, but it was fruitless, and Paredes was made prisoner. He was soon liberated and left the country.

Jack-in-the-box Santa Anna was still at Havana, whence he popped up at once and sailed for Mexico with his suite. He landed at Vera Cruz on the 16th of August, having passed the blockading squadron without question or delay. Of course he issued a manifesto denouncing the monarchical schemes of Paredes and the course of the United States, and explaining the merit of his own conduct. He then retired to his box to await the course of events, while he sent interested allies to the capital for the purpose of controlling them. State after state declared in favor of Santa Anna.

Every nerve was now strained to raise money and troops for the war. Santa Anna approached the capital, and was met by offers of the supreme power from the provisional government. They were declined on the ground that Santa Anna willed to serve his country in the army. He declared that he would not abandon the post of danger for the post of power, and closed his answer with assurances of his disinterested patriotism. This paved the way for his reception at the capital. He was received with a show of enthusiasm worthy of the regeneration of his country.

This parade of military ardor took place on the 15th of September, while General Ampudia was strengthening Monterey for the attack. A week later it had come, and on the 25th the city had capitulated.

On the 8th of October General Santa Anna arrived at San Luis de Potosi with the troops which had marched from Mexico. He at once set about organizing the large army called into the field, pledging a part of his private property as one means of raising money, which was sorely needed and hard to get.