On March 9, 1916, Mexican rebels led by Pancho Villa attacked the United States Army garrison at Columbus, New Mexico. All available troops were rushed to the United States - Mexican border, but there were not enough regulars to patrol such a vast area. On May 9, the National Guard of Arizona, New Mexico and Texas was called into Federal service. On June 18, the entire National Guard, except for coast artillery units, were called. Within days the first of 158,664 National Guardsmen were on their way to camps in Arizona, New Mexico and Texas. National Guard units began patrolling the border immediately and columns of Guardsmen soon dotted the desolate landscape from Arizona to Texas. Among the many units on the border was the 2nd Connecticut Infantry. On June 20, 1916, the regiment assembled and began preparations for the long rail journey to the border. Within a week they were on a troop train headed for Nogales, Arizona. Although their patrols along the border were important, the training that the Guardsmen received was invaluable. Guardsmen were physically toughened and officers and NCOs gained experience in handling troops in the field. The 2nd Connecticut mustered out of Federal service in November 1916, only to be mobilized again in February 1917. The training that the regiment received in Arizona would be important after the United States entered World War I two months later. Re-designated as the 102d Infantry and assigned to the famous 26th "Yankee" Division, the regiment fought in six World War I campaigns. The 102d Infantry, Connecticut Army National Guard continues its proud record of over 300 years of service to state and nation.