Villa's raid on Columbus triggered an immediate military response. March 10, 1916, the day after the attack, President Wilson decided to mount a punitive expedition to "pursue and disperse" the Villista rebels. Just as Villa had imagined, the inevitable clash between Carranza forces and American army troops happened within one month of the American intervention.
On April 12, 1916, the day after the last known contact between Villa and the American pursuers, Major Frank Tompkins, the officer who had so courageously hunted the raiders in the immediate aftermath of the Columbus attack, led a column of 140 men to the outskirts of Hidalgo del Parral. All intelligence assessments pointed to Villa having headed here. The Villista stronghold and hometown of Frederico Stallforth, over five hundred miles from the border, marked the farthest point south the Punitive Expedition would reach. The city of Parral was in the far Southwest corner of the state of Chihuahua. Tompkins proceeded with a small detachment to the guardhouse when he arrived at the outskirts of the proud mining town. There, he asked to see the Carrancista commander. General Ismael Lozano as well as the Presidente of Parral, José de la Luz Herrera, obliged and invited the American delegation into the prestigious city hall. Major Herrera was the father of Maclovio and Luis Herrera, two of Villa’s fiercest commanders who had recently switched sides and now supported Carranza. The Mexicans notified Tompkins that they wanted the American troops to leave town immediately. Tompkins brashly demanded supplies for his troops, which General Lozano arranged. However, while the men met in the city hall, “a huge mob led by a beautiful young woman named Elisa Griensen [from a prominent Parral family with Austrian background] had gathered. ‘Viva Villa! Viva Mexico!’ they shouted.
As the troops started out of town, other women leaned out of their second-floor windows and dumped their slop jars and spittoons onto the soldiers. Tompkins was infuriated and dropped behind to keep an eye on the crowd. One compactly built man, with a neat Vandyke beard and mounted on a very fine Mexican pony, seemed to be exhorting the mob to violence… Tompkins thought the man looked German and made up his mind to shoot this ‘bird’ first if violence did erupt.”
As the Carrancista jefe de armas tried to ferry the American soldiers out of town, shots rang out. Despite the Carrancista troops shooting into the crowd and trying to protect the Americans, Tompkins immediately deployed his squadron on two hills overseeing the road into Parral, as well as in a railroad embankment. General Lozano “begged Tompkins to retreat at once. But Tompkins would not be budged: ‘After we get our food and forage,’ he responded.” A shootout between the Carrancistas and the Americans ensued. Tompkins had to withdraw and fight a rear guard action for five miles. In the end, the American cavalry detachment had lost two soldiers and suffered six wounded. Among the Carrancista casualties were forty deaths, with an unknown number of wounded and killed civilians in Parral. .
General Pershing, upon learning of the firefight, decided to reinforce the American forces around Parral with more cavalry, a field artillery regiment, and two infantry regiments. Hundreds of American troops converged on the town. Tompkins, whose action had precipitated the escalation of the conflict and, against orders, had provoked the clash with Carranza’s forces, wrote in his memoirs, “We now felt as though our force was strong enough to conquer Mexico, and we were hoping the order to ‘go’ would soon come.” However, the order did not come. Under pressure as a result of stretched supply lines and the threat of more clashes with local Carranzista forces, General Pershing ordered U.S. forces to withdraw in the middle of April. Pershing mused in his memoirs, “the German Consul at Parral was instrumental in inciting the people.” While Frederico Stallforth’s brother never hinted at his involvement, Alberto Stallforth was the German consular agent (Parral did not have a consulate) and could very well have been behind the angry mob in Parral. As a result of the clash, Pershing changed his strategy from flying columns pursuing Villistas in the region to organizing regional camps that conducted patrols and prevented the use of the covered territory as a base of operations for Villa.
After the shootout at Parral, Venustiano Carranza issued another stern demand to President Wilson that the Americans leave Mexico. The Wilson administration responded, and asked for a meeting between Secretary of War Obregón and Generals Funston and Scott in Ciudad Juarez. The military commanders met on April 30. Obregón reiterated the unconditional demand of Venustiano Carranza for the Americans to withdraw. The meetings ended quickly because, according to Army Chief of Staff Scott, “General Funston allowed his real sentiments to be expressed so brusquely that he lost his influence in those conferences, and he thought it best for him not to attend anymore.” Scott’s decision to choose General Pershing over Frederick Funston for the sake of diplomacy seemed to have been the correct one. Scott succeeded, during subsequent private meetings on May 1 and 2, in getting Obregón to back down somewhat.