A type of middle and upper-class woman in the 1920s. They cut their hair into short bobs, wore short skirts, rolled down their stockings to reveal their knees, drank alcohol, and danced the Charleston. While few in number, their behavior was very public and raised concerns among traditionalists.

Nickname for the 1867 purchase of Alaska from the Russian Empire for a $7.2 million. So named because the Secretary of State brokered the deal for what was then popularly seen as a worthless icebox. Later, gold and oil were discovered in great quantities in Alaska, making the deal a steal. Russia sold Alaska to the United States to keep it out of the hands of its geopolitical rival, Britain, which seemed poised to eventually seize the land.

A term for journalism that produced juicy stories, both real and wildly sensationalized, designed to drive newspaper readership, sometimes at the expense of the truth. See: Joseph Pulitzer, muckrakers, Spanish-American War, William Randolph Hearst.

Added to the war declaration on Spain, it assured Cuba and the world that the United States intended to grant Cuba its independence once the war ended. This turned out not to be the case.

This war was ostensibly triggered by the alleged sinking of the Maine by Spanish forces, it involved the United States aiding independence efforts in Cuba to protect financial investments there, as well as to safeguard the Gulf Coast from a free Cuba potentially leasing its ports to foreign powers. The United States took control of Cuba, the Philippines, Puerto Rico, and several other islands.

A volunteer force of college students, cowboys, and adventurers led by Theodore Roosevelt during the Spanish-American War. They famously battled for control of San Juan Hill in Cuba with the heavy assistance of the Fourteenth Regiment Colored.

The peace treaty that ended the Spanish-American War. It turned Cuba, Guam, the Philippines, and Puerto Rico over to the United States. The treaty also signaled the end of Spain as a world power and the beginning of the United States as a rising one.

A 1901 court decision which ruled that a citizen in a conquered territory did not necessarily have the protection of the Constitution. It was up to Congress to decide the rights of the peoples in the newly conquered territories. See: Spanish-American War.

This was articulated by Secretary of State John Hay, who served in both the McKinley and Roosevelt administrations. It declared that China would be free to trade equally with any nation. The policy was wildly popular in the United States, as it kept Chinese markets open to American business while outwardly avoided the taint of imperialism. Unsurprisingly, it was denounced and resisted in China due to it being a thinly veiled justification for violating their sovereignty. Contributed to the outbreak of the Boxer Rebellion.

A 1903 policy issued by the U.S. after the Spanish-American War. Cuba had to have all treaties approved by the United States; the United States had the right to interfere in Cuban affairs both politically and militarily; and the United States would be given access to naval bases on the island.

A pejorative label for Teddy Roosevelt's foreign policy, especially in Panama, that referenced his repeated threats to use military force while negotiating peacefully.

An amendment to the Monroe Doctrine issued by Theodore Roosevelt. It stated that the United States would come to the aid of any Latin American nation experiencing financial trouble. In essence, the United States gained total control of Latin America through this amendment. See: Good Neighbor Policy.

A term for German submarines. Upon their introduction, they were seen as a ghastly weapon that violated the gentlemanly rules of warfare. The sinking of several ocean liners, such as the Lusitania, led to the deaths of American citizens and the entry of the United States into World War I. See: Zimmermann Telegram.

A diplomatic letter from German Foreign Secretary to the Mexican president, promising him that if his country assisted Germany in a possible war against the United States, Mexico would be given back the territory lost in the Mexican-American War. A contributing factor to U.S. entry into World War I.

A speech given by President Wilson in 1918. It outlined his vision for the war aims and peace terms of the United States in World War I.

An agency established by the federal government during World War I. It sought to control production, wages, and the prices of goods.

Commonly referred to simply as "The Draft." It provided for all American males between the ages of 21 to 35 to register for compulsory military service. This was the first time a peacetime military draft had been initiated, signaling that the president's stance was shifting from isolationism to interventionism.

A 1917 law aimed at German-Americans and antiwar activists. It prohibited interfering with military recruitment and any support of enemy nations in wartime. Although parts have been repealed over time, this act remains in effect, and has been used to prosecute people even in the 2010s. Used against many dissidents, from Eugene V. Debs to Daniel Ellsberg.

A law passed during World War I that limited the right to free speech. Antiwar activists and socialists, such as Eugene V. Debs, were targeted, arrested, and jailed.

This was proposed by Woodrow Wilson in his Fourteen Points. Article X of the League's charter called for members to stand at the ready if another member nation's sovereignty was being threatened. This killed the charter's chances of ratification in the U.S., as it seemed to promise future wars. See: reservationists, irreconcilables.

A group led by Republican senator Henry Cabot Lodge that agreed to ratify the League of Nations treaty only if reservations, such as the ability to leave the League and international acceptance of the Monroe Doctrine, were added to the League's covenant.

A group led by Senators Hiram Johnson and William Borah who refused to ratify the League of Nations treaty under any circumstances.

Ran from 1917 through the 1920s. A period of social anxiety and paranoia concerned with communist and anarchist infiltration throughout society. Driven by events such as the nationalism of World War I, labor unrest, nativism, and most especially the 1917 Russian Revolution that established the world's first communist state in the Soviet Union. Led to a series of mass arrests and deportations in 1919-1920 known as the Palmer Raids.

The peace treaty that officially ended World War I, but not ratified by the United States, which secured a separate peace in 1921. The treaty's terms were extremely harsh but, as time went on, laxly enforced, resulting in the worst of both worlds. They contributed to Germany's postwar economic turmoil while allowing for the rise of Adolf Hitler and the Nazi Party. See: Dawes Plan, Fourteen Points.