| Term | Definition |
| Isolationism | Having little to do with the political affairs of other nations. |
| Imperialism | The policy of powerful nations seeking to control the political and economic affairs of other nations. |
| Washington's Farewell Adress | "Have as little connection with foreign nations as possible," and "Steer clear of permanent alliances." |
| "White Man's Burden" | Idea that many European countries had a duty to spread their religion and culture to those they believed to be less civilized. |
| "Seward's Folly" | Many criticized William Seward's purchase of Alaska calling it his folly. |
| Open Door Policy | A policy proposed by the US in 1899, under which ALL nations would have equal opportunities to trade in China. |
| Spheres of Influence | An area where a nation had special trading privilages. |
| "Yellow Journalism" | A sensational and exaggerated style of writing that is often false. |
| "Remember the Maine" | Slogan/Rally cry in 1898 to drum support for war with Spain. |
| Commodore Matthew Perry | The commodore of the u.s. navy who compelled the opening of Japan to the west. |
| Alfred Thayer Mahan | United States naval officer and historian. |
| Queen Liliuokalani | The Hawaiian queen who was forced out of power by a revolution started by American business interests. |
| The Rough Riders | Cowboys, college students, and adventurers that went to war-led by Teddy Roosevelt. |
| Commodore George Dewey | A commodore during the Spanish-American War who captured the Philippines and Guam. |
| Emilio Aguinaldo | Filipino who lead both the Phillipine revolution against Spain and then the United States. |
| Theodore Roosevelt | 26th President of the United States. |
| Roosevelt Corollary | Allowed U.S. to be the "policeman" in Latin America. |
| William Randolph Hearst | United States newspaper publisher whose introduction of large headlines and sensational reporting changed American journalism (1863-1951). |
| Joseph Pulitzer | Owner of the New York World newspaper. |
| Mexican-American War | Armed military conflict between the United States and Mexico from 1846 to 1848. |
| Spanish-American War | An 1898 conflict between the United States and Spain, in which the United States supported Cubans' fight for indepedence. |
| Annexation of Hawaii | US overthrew Queen Liliuokalani in order to make Hawaii there own for its great location and farming conditions. |
| Boxer Rebellion | A 1900 Uprising in China aimed at ending foreign influence in the country. |
| Purchase of Alaska | When the US bought Alaska from Russia. |
| Building of the Panama Canal | The Panama Canal was constructed by the US to allow ships to reach the Pacific from the Atlantic. |
| Philippine Insurrection | Seceret orders for Roosevelt to block all ships leaving the asiatic coast if war was declared. |