Moreover it was not necessary to look across the ocean to foresee the necessity for military readiness. Our neighbor to the south was in the grip of armed lawlessness and terrorism. Northern Mexico was infested with banditti which were a constant menace to the safety of our border. Such government as the stricken country had was either unable or unwilling to hold them in check. It appeared to be inevitable that the United States, by armed intervention, must sooner or later come to the protection of its citizens. In that event the little handful of troops of the regular army must of necessity be reinforced by units of the state militia. It might be that soldiers of the National Guard would be used only for patrolling the border, and it might well be that they would be sent, as was one of Penfield Butler's ancestors, into the heart of Mexico to enforce permanent peace and tranquility at the point of the bayonet.
So this was the situation, and this was the appeal to Pen's patriotic ardor. And the appeal was a strong one. But he did not at once respond to it. His work and his study absorbed his time and thought. It was not until late in the fall of that year, the year 1915, when the crises, both at home and abroad, seemed rapidly approaching, that Pen took up for earnest consideration the question of his enlistment in the National Guard. Given by nature to acting impulsively, he nevertheless, in these days, weighed carefully any proposed line of conduct on his part which might have an important bearing on his future. But he resolved, after due consideration, to join the militia if he could.
He went to a young fellow, a wool-sorter in the mills, who was a corporal in the militia, to obtain the necessary information to make his application. The corporal promised to take the matter up for him with the captain of the local company, and in due time brought him an application blank to be filled out stating his qualifications for membership. It was necessary that the paper should be signed by his mother as evidence of her consent to his enlistment since he was not yet twenty-one years of age. She signed it readily enough, for she quite approved of his ambition, and she took a motherly pride in the evidences of patriotism that he was constantly manifesting.