federal service after the United States entered World War I in April 1917. Many National Guard leaders in both World Wars traced their first federal service to the Mexican Expedition. In their history of the call-up, Charles Harris and Louis Sadler reveal its significance: Between June 1916 and April 1917 the guard received intensive field training. Units from different states were sometimes grouped into large provisional units. Not only did the men become more proficient, but many officers gained invaluable experience commanding large formations. At the same time the guard was receiving badly needed equipment and supplies. The great call-up transformed the national guard into a much more effective fighting force, for it was as close as the United States came to the large-scale military maneuvers in which European armies traditionally engaged. Aftermath After U.S. forces were withdrawn in January 1917, Pershing publicly claimed the expedition to be a success, which in light of the public declarations by President Wilson was clearly not the case since Villa eluded capture by the U.S. Army. Pershing complained privately to his family that Wilson had imposed too many restrictions, which made it impossible for him to fulfill that portion of his mission. In the sting of the moment, having been compelled to withdraw out of political considerations and before much larger events in Europe put the episode behind him, he wrote that "Having dashed into Mexico with the intention of eating the Mexicans raw, we turned back at the first repulse and are now sneaking home under cover, like a whipped curr with its tail between its legs," referring to the massive rules of political restrictions put on him by President Wilson. During the three months of active operations, American forces killed or captured 292 Villistas and captured 605 rifles, 5 pistols, 14 machine guns, and 139 horses and mules from the Villistas. Most of the horses and mules were returned to local residents and the pistols kept as souvenirs. Pershing was permitted to bring into New Mexico 527 Chinese refugees who had assisted him during the expedition, despite the ban on Chinese immigration at that time under the Chinese Exclusion Act. The Chinese refugees, known as "Pershing's Chinese", were allowed to remain in the U.S. if they worked under the supervision of the military as cooks and servants on bases. In 1921, Congress passed Public Resolution 29, which allowed them to remain