As the new century loomed just over the horizon, the time seemed ripe for many Americans to look beyond their continental borders to a place of destiny in the world. Historian Frederick Jackson Turner had warned Americans, in his much-reproduced speech delivered at the 1893 Chicago World's Fair, that the new century would be the first in U.S. history in which no frontier existed for them to conquer. Many Americans interpreted this to mean that new frontiers were integral to national greatness. For example, Rear Admiral Alfred Thayer Mahan preached the doctrine of American expansionism in twenty books and numerous widely quoted essays. He asserted that no modern nation could be a great nation without a powerful navy, a superior merchant fleet, and overseas colonies. Turner's lectures and Mahan's writings greatly influenced political leaders like Theodore Roosevelt and Henry Cabot Lodge. These individuals looked beyond American shores for new frontiers, world markets, and overseas colonies.

American Empire

The quest for empire was not a universally accepted project, however. A sizeable number of Americans feared that overseas expansion would be too costly, would bring non-white peoples into the American nation, and would deviate from the traditional isolationist stance of the nation's foreign policy. Sugar producers in the lower South viewed the potential absorption of Puerto Rico, Cuba, and the Philippines as an economic threat. The "anti-imperialists," as their leading historian called them, included former Democratic presidential candidate William Jennings Bryan, author Mark Twain, and dissident Republicans like Andrew Carnegie and Benjamin Harrison. While the anti-imperialists came from different occupations, political parties, and ideological backgrounds, they all opposed territorial expansion.

Spanish-American War

In this contentious political atmosphere, McKinley was forced to deal with the problem of Cuba—a foreign policy issue the Cleveland administration had little success in solving. Spain's repressive rule over Cuba had caused the Cubans to revolt in 1895. Spain responded with ferocity, launching its reconcentrado campaign that herded 300,000 Cubans into camps where, the Spanish reasoned, they could not help the insurgents. Spain's brutal attempts to put down the rebellion infuriated many Americans, who began to raise money and even fight on the side of the Cuban nationalists. American businesses with economic interests on the island, moreover, worried about the safety of their investments. McKinley wanted an end to the Cuban-Spanish conflict but demanded that Spain act responsibly and humanely and that any settlement be acceptable to Cuban nationals. Throughout 1897, McKinley pressured Spain to make concessions to meet these ends.

In November 1897, a resolution appeared possible when the Spanish granted the Cubans limited autonomy and closed the reconcentration camps. But after pro-Spanish demonstrators rioted in Havana in January 1898 to protest Spain's more conciliatory policies, McKinley ordered the U.S. battleship Maine to Havana harbor, both to protect American citizens and property and to demonstrate that the United States still valued Spain's friendship. With the Maine safely moored in Spanish waters, the publication in the New York Journal of a letter, intercepted by Cuban nationals, written by Enrique Dupuy de Lome, Spanish minister to the United States, jolted the Spanish-American relationship. De Lome's letter described McKinley as "weak and a bidder for the admirations of the crowd . . .," and, more importantly, revealed that the Spanish were not negotiating in good faith with the United States. Americans saw the letter as an attack on both McKinley's and the nation's honor.

The public's anger only intensified following an explosion on the Maine and its sinking on February 15, 1898, in Havana Harbor, killing 266 crew members. McKinley ordered an investigation of the Maine explosion even while some Americans cried, "Remember the Maine! To Hell with Spain!" and pressed for war. As Spain and the United States searched earnestly and unsuccessfully for a diplomatic solution, the Navy, on March 21, reported that an external explosion, presumably from a Spanish mine, had destroyed the ship.

With his diplomatic initiatives exhausted and the American public wanting an end to the Cuban crisis, McKinley, in mid-April, asked Congress for authority to intervene in Cuba, which it granted. Spain soon broke relations with the United States, and the United States blockaded Cuba's ports. On April 23, Spain declared war on the United States, an act the United States returned in kind two days later. Congress added the Teller amendment to its declaration of war, committing the United States to the independence of Cuba once the war had ended, disclaiming "any disposition or intention to exercise sovereignty, jurisdiction or control over said island, except for the pacification thereof."

After the declarations of war, events moved quickly and decisively in America's favor. On May 1, Commodore George Dewey destroyed Spain's ten-ship Pacific fleet in Manila Bay without losing a single man. McKinley pushed through a joint resolution of Congress annexing the Hawaiian Islands. In Cuba, U.S. forces, including the Rough Riders led by Colonel Theodore Roosevelt, captured Santiago. The U.S. Navy destroyed Spain's Atlantic fleet in the waters between Cuba and Jamaica, and U.S. troops captured Puerto Rico. Spain sued for peace, and a cease-fire was declared on August 12. One day later, Commodore Dewey's forces completed their campaign against the Spanish in the Philippines by taking Manila. During the fighting, McKinley operated a war room from the White House, complete with detailed maps and a battery of telephones through which he kept in constant contact with his generals in the field. The war had lasted just over three months, and the Americans killed in action numbered less than 400, although many more had died from malaria, yellow fever, and other diseases.

The Paris Peace Treaty was signed on December 10, 1898. Under this treaty, the United States obtained Puerto Rico, Guam, and—for $20 million—the Philippine Islands. Spain also renounced its claim to Cuba, which remained under U.S. military occupation until 1902. Thereafter, Cuba would be a U.S. protectorate until 1934. Congress took nearly two months to ratify the treaty, but did so—securing the necessary two-thirds majority by a single vote—on February 6, 1899. Despite the heated debates and protests of congressional lawmakers, McKinley was able to secure the treaty's approval and to convince the House to appropriate funds for implementing and building the American empire. In demonstrating his political influence on the outcome of these matters, McKinley became the undisputed leader of the Republican Party. Furthermore, his actions represented a real expansion of presidential power at the turn of the century. Under McKinley's leadership, the United States had become one of the world's colonial powers.

Filipino Revolt

Almost as soon as the war with Spain had ended, a grassroots insurgency broke out in the Philippines led by Filipino nationalist Emilio Aguinaldo. McKinley responded by sending thousands of American marines and sailors to the islands. This action engaged the nationalists in a bloody war that left the United States open to atrocity charges similar to those lodged against Spain in its dealings with Cuba and the reconcentration camps. The war lasted until 1902, and before it was over, it claimed the lives of more than 5,000 Americans and some 200,000 Filipinos.

Open Door Trade Policy in China and the Boxer Rebellion

American interests in Asia were not limited to the Philippines. China emerged as a major foreign policy concern for the McKinley administration, especially as Britain, Germany, France, Russia, and Japan, among others, scrambled throughout the 1890s to establish their own "spheres of influence" in that nation. Fearful that the Europeans and Japanese might close Chinese ports to U.S. commerce, McKinley authorized Secretary of State John Hay to issue an "Open Door" note on China. This circular strongly expressed the American desire to place all commercial nations on an equal footing in China, unencumbered by discriminatory tariffs or other restrictions. It also declared U.S. support for a non-colonized and independent China. The "Open Door" policy stands as one of the most important policy statements ever issued by the U.S. State Department.

In June 1900, a group of Chinese nationalists who objected to foreign intrusions in their country massacred numerous western missionaries and Chinese converts to Christianity. Popularly known as the Boxers, this group also laid siege to the foreign community of diplomats in Peking. McKinley dispatched 2,500 U.S. troops—without seeking congressional approval—and several gunboats to assist a combined expeditionary force of British, German, Russian, and Japanese troops in the liberation of the foreign delegations. Secretary of State John Hay issued a second "Open Door" note in the midst of the Boxer Rebellion that warned America's expeditionary partners that the United States supported intervention only to rescue the diplomats, not to bring China under European and Japanese control. By August, the allied force had successfully put down the Boxer Rebellion. China was forced to pay an indemnity in excess of $300 million, $25 million of which went to the United States.