The incident on the border happen while the war was ending and Grant was Commanding General.
Grant was also concerned about the situation in neighboring Mexico, where 40,000 French soldiers were propping up the puppet regime of Austrian Archduke Maximilian, and gave Sheridan permission for a large Texas occupation force. Sheridan assembled 50,000 men in three corps, quickly occupied Texas coastal cities, spread inland, and began to patrol the U.S.-Mexico border. The Army's presence, U.S. political pressure, and the growing resistance of Benito Juárez induced the French to abandon their claims against Mexico and Napoleon III withdrew his troops in 1866. Sheridan later admitted in his memoirs that he had supplied arms to Juárez's forces: "... supplied with arms and ammunition, which we left at convenient places on our side of the river to fall into their hands."