One hundred years ago, Mexico was wracked by a civil war, as rival factions vied for power: Venustiano Carranza, backed by the United States, versus Emiliano Zapata, a revolutionary who was supported by renowned fighter Pancho Villa.

In a series of battles, the U.S.-backed forces defeated the revolutionaries, so that by the end of 1915 most of Mexico was controlled by Carranza. In a desperate gamble to try to get the U.S. involved in the war, Villa began raiding border towns in New Mexico.

In response, the U.S. commander of Fort Bliss, Brigadier General John J. Pershing, mounted raids — to which there were counter-raids — into 1916. Tensions between the two countries grew.

To help the border states, President Woodrow Wilson authorized the activation of some 140,000 National Guardsmen from across the nation in what has since been referred to as “ The Great Call-up.”

This June will mark the 100th anniversary of the National Guard’s service on the Mexican border, a little-remembered event in Maine’s history. But for the men who traveled to Texas in 1916, it was one of the most exciting events of their lifetime — at least it would have been but for their service less than one year later in World War I.

On June 19, 1916, orders arrived at the adjutant general’s office at Camp Keyes in Augusta. The Second Maine Infantry Regiment — a descendant of the old Civil War Second Maine Volunteer Infantry Regiment — was to go to the border. At the time, the Maine National Guard consisted of the Second Maine and 13 numbered batteries of coast artillery regiments.

Instead of remove the coast artillery from their vital position defending Maine’s shores, only the infantry regiment would be sent to the border. This caused much unhappiness in the coast artillery outfits, and many men requested transfers to the infantry to be part of the “big show.” Rumors abounded that the coast artillery would be called up, but this announcement never came to fruition.

From June 19 to 28, the Second Maine gathered at Camp Keyes and was recruited to full strength under the command of Col. Frank Hume. Many men joined just for the opportunity for adventure. The entire University of Maine band joined up, becoming the regiment’s band section. It was the only college band in the entire U.S. Army.

Incidentally, the band leader was Adelbert W. Sprague, the man who set the “Maine Stein Song” to music. This song would not only become Maine’s state song but also the regimental march of the 103rd Infantry Regiment, which is what the Second Maine would become in World War I.

On June 29, the men of the Second Maine boarded trains for Laredo, Texas. For two days they traveled in uncomfortable day coaches with three men to a seat. When they reached Kansas City, they were switched to sleeper cars, which were far more comfortable and allowed the men to get some sleep. The 1,043 men of the Second Maine arrived in the important border town of Laredo on July 4.

Two years later to the day, most of these same men would arrive at Belleau Wood, France, to relieve the Marines there in some of the worst combat of World War I. But this was all in the unknown future to the Maine men, who quickly set up a neat and orderly camp outside the town and began settling in.

On July 17, morale was greatly lifted when the Mainers received light khaki uniforms to replace their heavy woolen ones. This was a great relief, as the heat was something to which the Mainers were ill-accustomed. The three battalions of the regiment prepared to take over patrolling duties from other units in the area that were leaving.

The Second Maine shared their duties in Laredo with National Guardsmen from Missouri and New Hampshire, as well as several outfits of active duty soldiers, referred to as Regulars. Conditions at Laredo were generally good: The Army supplied good food and required the local municipality to put in modern plumbing and medical facilities.

When not on duty, troops could go into town to take in a movie or go shopping for souvenirs, which they would then send home. The regimental bands made quite an impression, holding frequent concerts in the town square, for soldiers and civilians alike. One incident of note was that the Mainers on border service were allowed to cast absentee ballots for the Maine gubernatorial election that year.

But the Second Maine was there to establish security, and the soldiers grew restless at not being used. At the end of July, the regiment was broken up by companies and sent out to secure San Ignacio, Zapata, and various crossings along the Rio Grande. Here, the Maine men learned how to march long distances with full packs and equipment, how to set up outposts and how to sustain themselves as soldiers. It was a valuable learning experience for all of the men, especially the officers.

By September, the Second Maine was assembled in Laredo again. In a short time, they were relieved by the Second Florida Infantry and were on their way home again. The city of Laredo was sad to see them go.

The city newspaper wrote, “Laredo regrets to lose the Maine boys and their excellent college band. Since their coming here they have made an excellent reputation as gentlemen as well as soldiers and leave Laredo with a clean record, not a single one of their men having been arrested for any violation of the civil law while here.”

The Second Maine was mustered out of active service and returned to the control of the Maine National Guard in Augusta on Oct. 28, 1916.

Less than six months later, the men would be called back into federal service, this time bound for France. The officers and men of the Second Maine — now the 103rd U.S. Infantry in 1917 — would take the lessons they learned on the Mexican border and apply them in combat in World War I.

First Lt. Jonathan Bratten is the Maine National Guard historian.