William McKinley in the context of "Gold Standard Act"

The Spanish–American War (April 21 – August 13, 1898) was fought between Spain and the United States in 1898. It began with the sinking of the USS Maine in Havana Harbor in Cuba, and resulted in the U.S. acquiring sovereignty over Puerto Rico, Guam, and the Philippines, and establishing a protectorate over Cuba. It represented U.S. intervention in the Cuban War of Independence and Philippine Revolution, with the latter later leading to the Philippine–American War. The Spanish–American War brought an end to almost four centuries of Spanish presence in the Americas, Asia, and the Pacific; the United States meanwhile not only became a major world power, but also gained several island possessions spanning the globe, which provoked rancorous debate over the wisdom of expansionism.

The 19th century represented a clear decline for the Spanish Empire, while the United States went from a newly founded country to a rising power. In 1895, Cuban nationalists began a revolt against Spanish rule, which was brutally suppressed by the colonial authorities. W. Joseph Campbell argues that yellow journalism in the U.S. exaggerated the atrocities in Cuba to sell more newspapers and magazines, which swayed American public opinion in support of the rebels. But historian Andrea Pitzer also points to the actual shift toward savagery of the Spanish military leadership, who adopted the brutal reconcentration policy after replacing the relatively conservative Governor-General of Cuba Arsenio Martínez Campos with the more unscrupulous and aggressive Valeriano Weyler, nicknamed "The Butcher." President Grover Cleveland resisted mounting demands for U.S. intervention, as did his successor William McKinley. Though not seeking a war, McKinley made preparations in readiness for one.

The length of a full four-year term of office for a president of the United States usually amounts to 1,461 days (three common years of 365 days plus one leap year of 366 days). The listed number of days is calculated as the difference between dates, which counts the number of calendar days except the first day (day zero). If the first day were included, all numbers would be one day more, except Grover Cleveland would have two more days, as he served two full nonconsecutive terms.

Of the individuals elected president, four died of natural causes while in office (William Henry Harrison, Zachary Taylor, Warren G. Harding, and Franklin D. Roosevelt), four were assassinated (Abraham Lincoln, James A. Garfield, William McKinley, and John F. Kennedy), and one resigned from office (Richard Nixon).

Frederick Victor Gillam (c. 1858 – January 29, 1920) was an American political cartoonist, known for his work in Judge magazine for twenty years, as well as the St. Louis Dispatch, Denver Times, New York World, and New York Globe. He was a member of the New York Press Club and Lotos Club. Born in Yorkshire, England, he emigrated to the United States at age six.

His notable work included support of William McKinley's 1896 presidential campaign. The younger brother of famed cartoonist Bernhard Gillam (1856–1896), he signed his work "Victor" or "F. Victor" until his brother's death. Victor died (aged 61-62) at Kings County Hospital and was buried in Evergreens Cemetery, Brooklyn.

The Foraker Act (Pub. L. 56–191, 31 Stat. 77, enacted April 12, 1900), officially called the Organic Act of 1900 and most commonly known by the name of its sponsor, Senator Joseph B. Foraker, (R-Ohio), is an organic act of the 56th United States Congress that was signed into law by President William McKinley on April 12, 1900. The Act replaced the military government of Puerto Rico, which was established by the United States after the annexation of the archipelago and island during the Spanish–American War in 1898, with a civil insular government under the continued federal jurisdiction of the United States as the local administration of an unincorporated territory. It served as the primary organic law for the government of Puerto Rico and its relation with the United States until it was superseded by the Jones–Shafroth Act of 1917.

The Foraker Act established a civil government in Puerto Rico modeled after the federal government of the United States. It divided the local government of the unincorporated territory into three branches: an executive, consisting of a Governor and an 11-member Executive Council appointed by the President of the United States, a legislative, composed of bicameral Legislative Assembly, with the Executive Council as its upper chamber and a 35-member House of Delegates elected by the residents of Puerto Rico as its lower chamber, and a judicial, headed by a chief justice and a district judge appointed by the President. The Act created the office of Resident Commissioner, a non-voting member to the United States House of Representatives elected by the residents of Puerto Rico. It also established Puerto Rican citizenship and extended American nationality to Puerto Ricans.

Theodore Roosevelt Jr. (October 27, 1858 – January 6, 1919), also known as Teddy or T. R., was the 26th president of the United States, serving from 1901 to 1909. Roosevelt previously was involved in New York politics, including serving as the state's 33rd governor for two years. He served as the 25th vice president under President William McKinley for six months in 1901, assuming the presidency after McKinley's assassination. As president, Roosevelt emerged as a leader of the Republican Party and became a driving force for anti-trust and Progressive Era policies.

A sickly child with debilitating asthma, Roosevelt overcame health problems through his strenuous life. He was homeschooled and began a lifelong naturalist avocation before attending Harvard University. His book The Naval War of 1812 established his reputation as a historian and popular writer. Roosevelt became the leader of the reform faction of Republicans in the New York State Legislature. His first wife Alice Hathaway Lee Roosevelt and mother Martha Bulloch Roosevelt died on the same night, devastating him psychologically. He recuperated by buying and operating a cattle ranch in the Dakotas. Roosevelt served as the assistant secretary of the Navy under McKinley, and in 1898 helped plan the successful naval war against Spain. He resigned to help form and lead the Rough Riders, a unit that fought the Spanish Army in Cuba to great publicity. Returning a war hero, Roosevelt was elected New York's governor in 1898. Because the New York state party leadership disliked his ambitious state agenda, they convinced McKinley to choose him as his running mate in the 1900 presidential election. The McKinley–Roosevelt ticket won a landslide victory.

A front porch campaign is a electoral campaign used in American politics in which the candidate remains close to or at home where they issue written statements and give speeches to supporters who come to visit. The candidate largely does not travel around or otherwise actively campaign. The presidential campaigns of James A. Garfield in 1880, Benjamin Harrison in 1888, William McKinley in 1896, and Warren G. Harding in 1920 are perhaps the best-known front porch campaigns. Joe Biden is considered to have run a "virtual" front porch campaign in 2020.

William Howard Taft (September 15, 1857 – March 8, 1930) was the 27th president of the United States from 1909 to 1913 and the tenth chief justice of the United States from 1921 to 1930. He is the only person to have held both offices.

Taft was born in Cincinnati, Ohio. His father, Alphonso Taft, was a U.S. attorney general and secretary of war. Taft attended Yale and joined Skull and Bones, of which his father was a founding member. After becoming a lawyer, Taft was appointed a judge while still in his twenties. He continued a rapid rise, being named solicitor general and a judge of the Sixth Circuit Court of Appeals. In 1901, President William McKinley appointed Taft civilian governor of the Philippines. In 1904, President Theodore Roosevelt made him Secretary of War, and he became Roosevelt's hand-picked successor. Despite his personal ambition to become chief justice, Taft declined repeated offers of appointment to the Supreme Court of the United States, believing his political work to be more important.

The Committee of Safety, formally the Citizen's Committee of Public Safety, was a 13-member group of the Annexation Club. The group was composed of mostly Hawaiian subjects of American descent and American citizens who were members of the Missionary Party, as well as some foreign residents in the Hawaiian Kingdom. The group planned and carried out the overthrow of the Hawaiian Kingdom on January 17, 1893. The goal of this group was to achieve annexation of Hawaii by the United States. The new independent Republic of Hawaii government was thwarted in this goal by the administration of President Grover Cleveland, and it was not until 1898 and under the administration of William McKinley that the United States Congress approved a joint resolution of annexation, creating the U.S. Territory of Hawaii.