This is an extremely rare find. The Mexican Border War, also known as the Border Campaign, refers to a series of military engagements which took place between the United States military and several Mexican factions in the Mexican-American border region of North America during the Mexican Revolution. It was the last major conflict fought on U. In 1916, President Woodrow Wilson called up the National Guard to active duty for the first time in the 20th century. The mobilization was a response to the threat of war with Mexico, and the need to protect the border and capture Francisco “Pancho” Villa. The call-up was the first nationwide mobilization of the National Guard in American history.