Rancho de Carricitos was a large farm field fenced in by high, impenetrable chaparral thickets that gave the location its name. The ranch was located on the north bank of the Rio Grande, some 28 miles upriver from the U.S. post, Fort Texas.

On the morning of April 25, 1846, Captain Seth Thornton's party of U.S. Dragoons approached this ranch, looking into reports that a large force of Mexican troops had crossed the river the previous day. Spotting a small cluster of houses within the clearing, the 63 men decided to investigate. They located a narrow break that served as the only gate through the brush, and proceeded toward huts at the far end of the field.

A Mexican force had indeed crossed the river. The previous day, Mexican General Anastasio Torrejón led almost 1,600 cavalry and infantry troops over the Rio Grande and took up a position on the north bank. From this point, Torrejón marched east, responding to his own scouting reports of Thornton's approach.

When the Mexican troops arrived at Rancho de Carricitos, they located the Americans inside the fenced field. Unseen by the U.S. party, Torrejón first sent portions of his force to surround the field and close off any escape routes through the brush. Then, he ordered infantry troops to march through the gateway and form lines to block the exit from the ranch.

The sudden appearance of the Mexican forces took the U.S. troops by surprise. With their backs to the river and unpassable brush on each side, Thornton and his troops had no option but to charge the Mexican line. Heavy gunfire, however, turned the horsemen aside. Thornton's men then dismounted and attempted to cut their way through the chaparral fence, only to be stopped by the Mexican troops outside the field.

The U.S. troops again circled the ranch in search of an exit, but to no avail. As Mexican cavalry troops poured into the clearing, the Dragoons surrendered. Eleven American soldiers lay dead on the field, 46--including Captain Thornton--were taken captive. Mexican forces suffered only a few minor injuries.

News of the skirmish reached Zachary Taylor in Fort Texas later that day, and the General forwarded word to U.S. President Polk that hostilities had commenced.

The brief battle had two important effects. In the United States, news of the skirmish reached Washington D.C. on May 10, 1846. There, inspired by President Polk's impassioned announcement that "American blood has been spilled upon the American territory," Congress declared war on May 13. In Mexico, the skirmish provided the military leadership with a certain level of confidence in their ability to stand up to U.S. troops. This confidence, however, would be severely shaken in the aftermath of the next round of battles.

The site today
In the century and a half since the skirmish at Carricitos, the exact location of the ranch has been forgotten. Soldiers measured the distances to the site along the winding path of the Rio Grande--a river that has shifted course numerous times since 1846. The State of Texas has attempted to commemorate this clash with a roadside monument, approximately 25 miles west of Brownsville, Texas.

Palo Alto Battlefield National Historical Park continued to perform surveys and research that may, in time, pinpoint the exact location of the Rancho de Carricitos skirmish. In the meantime, somewhere amidst the lush cane fields, rich soil, and dense chaparral of the modern Rio Grande Valley the spot where war began in 1846 remains hidden.