And, in truth, the laws gave the President of the United States no authority to play the role of arbiter in a strike. His plain duty was to keep the peace. If a strike resulted in violent disorders he could send United States troops to quell them, but only in case the Governor of the State in which the riots occurred declared himself unable, by the State force at his command, to keep the peace, and requested assistance from the President. In the coal strike the Governor of Pennsylvania, for reasons which I need not discuss here, refused to call for United States troops, and so did the Pennsylvania Legislature. Roosevelt acted as a patriotic citizen might act, but being the President, his interference had immensely greater weight than that of any private citizen could have. He knew the law in the matter, but he believed that the popular opinion of the American people would back him up. In spite of the first rebuff, therefore, he persuaded the miners and the operators to agree to the appointment of an arbitration commission, and this suggested a settlement which both contestants accepted. It ended the great coal strike of 1902, but it left behind it much indignation among the American people, who realized for the first time that one of the three or four great industries essential to the welfare and even to the life itself of the Nation, was in the hands of men who preferred their selfish interests to those of the Nation. It taught several other lessons also; it taught, for instance, that great combinations of Labor may be as dangerous as those of Capital, and as heedless of everything except their own selfish control. It taught that the people of the States and of the Nation could not go on forever without taking steps to put an end to the already dangerous hostility between Capital and Labor, and that that end must be the establishment of justice for all. An apologist of the "coal barons" might have pleaded that they held out not merely for their private gain on that occasion, but in order to defeat the growing menace of Labor. Their stubbornness might turn back the rising flood of socialism. Respecters of legal precedent, on the other hand, criticised the President. They acknowledged his good intentions, but they pointed out that his extra-legal interference set an ominously bad example. And some of them would have preferred to go cold all winter, and even to have had the quarrel sink into civil war, rather than to have had the constitutional ideals of the Nation distorted or obscured by the President's good-natured endeavor. Roosevelt himself, however, never held this opinion. In 1915, he wrote to Mr. Washburn: "I think the settlement of the coal strike was much the most important thing I did about Labor, from every standpoint."