Clemente Vergara was a South Texas rancher whose murder by Mexican troops in February 1914 outraged Texans and increased tension between Mexico and the United States. Vergara was a native of Laredo and took over his father's ranch near Palafox after his father retired. He allowed his horses to graze on an island in the Rio Grande. This land was disputed, and it is unclear whether it belonged to the United States or Mexico. Vergara suspected that federal troops from Mexico had stolen eleven of his horses from the island. He reported the theft to Webb County Sheriff Amador Sánchez, who arranged a meeting between Vergara and Mexican Capt. Apolonio Rodríguez, commander of the Hidalgo federal garrison, under the pretext of compensating Vergara for the loss of his horses. Vergara's wife and Texas Rangers warned him against the meeting; however, on the morning of Friday, February 13, Vergara and a nephew crossed the Rio Grande to meet with several soldiers who called the two men over. Vergara was struck on the head and carried to the Hidalgo garrison, while his nephew escaped and returned to the United States. Mrs. Vergara and her daughter crossed into Mexico on February 14 in search of Clemente Vergara. They found him severely beaten and jailed in the Hidalgo garrison. They cleaned his wounds and remained with him until late that evening and spent the night with friends in Hidalgo. The following morning soldiers returned the bedding the Vergaras had taken to the jail for Clemente Vergara and told the women that he had been taken to Piedras Negras. The women returned to the garrison to speak with Captain Rodríguez, but he had already left.
Texas Governor Oscar B. Colquitt asked attorney general B. F. Looney if any charges could be brought against the Mexican officers. Looney advised the governor that the only crime that occurred on Texas soil was horse theft, which was an extraditable crime. Colquitt wanted to extradite Rodríguez and others involved in the incident with the help of the Texas Rangers if necessary. United States Secretary of State William Jennings Bryan stated that use of the Rangers would constitute an invasion of Mexico, an act only the federal government had the authority to permit. He directed Colquitt to inquire to the governor of Nuevo León, Mexico, or to the chief executive officer of Mexico about extradition charges. This was a vague directive because there were two governors, and both the Venustiano Carranza and Victoriano Huerta governments were seeking American recognition. On February 16 the federal commander at Piedras Negras reported that he ordered Vergara's release and the return of his horses, however, on February 25 witnesses told American officials that they had seen Vergara's body hanging from a tree near Hidalgo, and that it had been there since February 15. Vergara's body was finally "delivered" to his relatives in Texas on March 7. There is some controversy about how the body was recovered. Headlines reported that the Texas Rangers had retrieved the body from a shallow grave in the Hidalgo cemetery. Still other sources maintained that the body had been found by the bank of the Rio Grande after the Vergara family had paid for its recovery. Some Mexican officials said that Vergara had not been killed but had escaped and joined the rebels.
The kidnapping of Vergara and other American citizens further outraged many people against President Wilson's Mexico policy and placed the Texas governor in direct opposition with the president. There had been, however, some vague speculation that Vergara had been smuggling guns across the border for Constitutionalists, but this suspicion was never confirmed. Colquitt announced at a speech to the Cattle Raisers Association of Texas a $1,000 reward for the arrest of Vergara's murderers and challenged Senator John Morris Sheppard to resign for supporting Wilson's policy. Wilson responded by moving more troops along the Mexican border. The incident pitted the Wilson administration against the Texas governor and was another example of the use of the Texas Rangers as a paramilitary state police force.