More important than the steel strike in its effect upon the public was the strike of the miners in the anthracite coal fields of Pennsylvania. In 1900 these workers were organized by the United Mine Workers of America, under the leadership of John Mitchell. They gained concessions in a strike in this year, partly because the strike threatened to disturb political conditions and embarrass the Republican national ticket. The mine-owners, most of whom were Republicans, were persuaded by Hanna and others to end the quarrel.

In the spring of 1902 the strike broke out again, turning largely upon the question of the formal recognition of the union. All through the summer John Mitchell held his followers together, gaining an unusual degree of public sympathy for his cause. In the autumn, with both sides obstinate, a third party, the public, took an interest in the strike. The prospect of a coalless winter alarmed political leaders and citizens in general. It was felt that public interest was superior to the claims of either contestant, but there was neither law nor recognized machinery through which the public could protect itself. At this stage, in October, 1902, President Roosevelt secretly reached the intention "to send in the United States Army to take possession of the coal fields" if necessary. He called the operators and Mitchell to a conference at the White House, spoke to them as a citizen upon their duty to serve the public, and with rising public opinion behind him and supporting him, forced the owners to consent to an arbitration of the points at issue. The men returned to work, pleased with the President, to whose interference they and the public owed industrial peace.

In 1903 another miners' union, the Western Federation of Miners, conducted a great strike in the mines of Cripple Creek. Public opinion in Colorado knew no middle class. The miners and the operators represented the two chief interests of the section. Hard feeling and violence accompanied the strike. The malicious murder of non-union men added to the bitterness, which the presence of the militia and a series of arbitrary arrests could not allay. The strike was complicated by the presence among the workers of a strong element of Socialists, whose ends were political as well as economic. The leaders of the Federation, Moyer and Haywood, were Socialists, and for them the strike was only a beginning of political revolution. The strike lasted until the outraged citizens of Cripple Creek formed a vigilance committee and deported the chief agitators to Kansas.

Socialism played an increasing part in labor discussions after 1897. A Socialist Labor party had presented a ticket and received a few votes in 1892 and 1896, but socialism had not taken a strong hold on the American imagination. The swelling immigration that followed the new prosperity brought new life to socialism. In 1900 a Social Democratic party polled 94,000 votes for Eugene V. Debs for President. In 1904, with the same candidate, it received 402,000 votes. Society was reorganizing amid the industrial changes, while the discontented classes were growing more coherent and constructive.

President Roosevelt met the changes in transportation, industry, and labor with vigor. He invoked the Sherman Law against the Northern Securities Company. He brought suits against certain of the trusts which he stigmatized as the "bad trusts." Not all concentration, he urged, was undesirable. Capital, like labor, had its rights, but it must obey the law. Partly through his efforts Congress created in 1903 a new administrative department of Commerce and Labor. George B. Cortelyou became the first Secretary of this department. Through its Bureaus of Corporations and of Labor there was new activity in the investigation of the facts of the industrial movement.

The vigor with which the President directed foreign relations, interfered in big business, and espoused the cause of labor produced a breach between him and many of the regular leaders of the party. Through two campaigns Marcus A. Hanna had worked on the theory that the Republican party was the party of business, and had attracted to its support all who believed this or had something to make out of it. Many of these Republicans could not understand what Roosevelt was trying to do, and maintained an opposition, silent or open, to his policies.

The popularity of Hanna was used by many Republicans to offset the popularity of Roosevelt. Before 1896 Hanna had taken little part in public politics. Entering the Senate in 1897, he developed great influence. By 1900 he began to speak in public with directness and effect, and to undo the work of the cartoonists who had misrepresented his character. He interfered to bring peace in the anthracite regions in 1900, became interested in the labor problem on its own account, and discovered that he was popular. He was essentially a direct and honest man, who had had no reason to doubt that it was the chief end of government to conserve business. As he came into touch with public affairs he broadened, saw new responsibilities for capital, and had a new understanding of the wants of labor. The only personality that even threatened to rival that of Roosevelt in 1904 was that of "Uncle Mark" Hanna.

Roosevelt had been made Vice-President to get rid of him in New York. The single life that stood between him and the White House was removed by an assassin, and as a President by accident he desired to establish himself and secure a nomination on his own account in 1904. By the summer of 1902 he appreciated the growing interest in the problems of capital and labor. A speaking tour in 1902 gave him a chance to demand a "square deal" for all, and the control of the trusts. From some sections of the West came the suggestion that the way to approach the trusts was through the tariff.

The Dingley Tariff was unpopular with the Republican farmers of the Northwest, and for some years they tolerated it in silence as a test of party loyalty. In 1902 a liberal faction, controlled by Governor Albert B. Cummins, captured the Iowa convention and demanded a revision of the more extreme schedules. The belief that the tariff was the "mother of trusts" was spreading, and the Iowa idea gained wide acceptance. In Congress, in the session of 1902, the Republican organization had shown the stubbornness with which any opening in the tariff wall would be opposed.

Cuba was set free in the spring of 1902, her government having been formed under the guidance of the United States. The duty to aid the young Republic, and in particular to mitigate the severities of the Dingley Tariff impressed the President, who used all his influence to get such legislation from Congress. He failed signally, raising only a new issue by his attempt to coerce Congress. His speeches in the summer showed a willingness to revise the tariff, while his interference in the coal strike in the autumn showed his willingness to oppose the ends of capital. How far he would go in breaking with the leaders of his party was unknown, but their disposition to "stand pat" and do nothing with the tariff was marked before the end of 1902.