ARLINGTON, Va. - On March 9, 1916, the pounding of hooves broke the early-morning silence as mounted riders descended on Columbus, New Mexico. Under the command of the rebel Gen. Francisco "Pancho" Villa, more than 400 Mexican revolutionaries from nearby Chihuahua looted businesses, shot citizens and set fires in the small American border town.
There were casualties on both sides. Mexican riders killed ten civilians and eight Soldiers of the 13th U.S. Cavalry from nearby Camp Furlong, but the Villistas lost even more. American Soldiers and civilians killed as many as 90 and wounded 13 revolutionaries. Defeated, the insurgents returned to Mexico, signaling the end of the first foreign invasion of U.S. territory since the Battle of New Orleans in January, 1815. This attack would mark the beginning of a new era in the history of the National Guard, America's oldest military organization.

American leaders were quick to react. President Woodrow Wilson was furious upon hearing the news. Meanwhile, the senator from North Dakota, Porter McCumber, quickly placed a resolution on the Senate floor directing the War Department to launch a coordinated response to the Villistas.

The New Mexico National Guard immediately responded to the attack. Soldiers from Company I, 1st New Mexico Infantry, gathered at the Deming Armory 30 miles north of Columbus and mobilized to support the 13th Cavalry at the site of the raid. The participation of the New Mexico National Guard was the first of a major mobilization and deployment to protect America's southern border.

The resultant "Punitive Expedition," led by Brig. Gen. John J. Pershing on March 14, attempted to apprehend Villa and the rebel army in his home state of Chihuahua. The U.S. government wanted Villa brought to justice, dead or alive. Yet sending resources into Mexico underscored the vulnerability of the active component of the U.S. Army, given the troubles along the U.S.-Mexico border.

Earlier in the Mexican Revolution, which started in earnest in early 1911, Villa went to great lengths to avoid harm to American citizens in Mexico as well as their property. However, the United States government recognized rival Venustiano Carranza as president of Mexico in 1915 and turned Villa and his followers squarely against the U.S. This stance took a violent turn when Villistas stopped a train in Chihuahua and proceeded to assassinate 16 American mining engineers near the town of Santa Ysabel in January 1916. After menacing much of the Mormon colonies of northern Chihuahua through the winter, Villa's band proceeded with the Columbus attack.

After Columbus, small Mexican rebel ambushes continued, in the small hamlets of Glenn Springs and Boquillas in west Texas on May 5 only added to the worry. This volatility later made it necessary for the president to federalize the National Guard. Three of the four border states, Arizona, New Mexico, and Texas, sent nearly 4,200 troops to the region to supplement military firepower and discourage further banditry.

In addition to the military response, hard-fought legal battles about national preparedness that sprang up in the House of Representatives offered a solution to the urgent need to protect the vulnerable Southwest borderlands. This statute eventually became the National Defense Act of 1916, signed into law by the president on June 3, 1916. An unprecedented mobilization of the entire National Guard would then follow on June 18.

The chain of events in just over a year would catapult the United States into international warfare soon after its entry in World War I in April 1917, and it emerged as a world leader and through the Allied victory in late 1918. But the Columbus raid served to shock the nation and became the harbinger for many other events that produced far-reaching change across the globe 100 years ago.

Villa escaped American justice but his luck ran out on July 20, 1923, when assassins riddled his car with 40 bullets, killing him, his chauffeur and an assistant.