| Term | Definition |
| Boxers | A secret group of Chinese who attacked foreigners in China. |
| Queen Liliuokalani | Leader of Hawaii who took the throne after her brother died. Was forced to give up her throne when the U.S. marines were sent. |
| William Seward | Purchased Alaska for the U.S. from Russia for $7.2 million |
| Alfred Mahan | Captain of the U.S. Navy who was for imperialism. He thought that a bigger navy was needed to protect American ships. |
| Rough Riders | Led by Teddy Roosevelt. It was the First Volunteer Cavalry Regiment which led a Battle of San Juan Hill. They were victorious! |
| Matthew Perry | Opened Japan to trade with the U.S. Best known for his statement: "San Juan was the greatest day of my life." |
| John J. Pershing | Led American troops into Mexico in 1916. |
| Emilio Aguinaldo | Fought for Philippine independence. |
| Pancho Villa | Raided Columbus, New Mexico in 1916. |
| William Seward | Purchased Alaska for 7.2 million dollars. People called his purchase "Seward's Folly." |
| President Teddy Roosevelt | Under his presidency, the U.S. gained control of the Panama Canal Zone. Best known for his statement: "Speak softly and carry a big stick and you will go far." |
| American sugar planters in Hawaii | Wanted to annex the Hawaiian islands. |
| Yellow journalism | The process of exaggerating news in order to attract readers. This happened after the ship Maine exploded. |
| Treaty of Kanagawa | Resulted in the opening of two Japanese ports to trade as well as Japan helping shipwrecked sailors. |
| Platt Amendment | Under this amendment, Cuba had a restricted amount of independence. The U.S. was even allowed to get involved in Cuba's business! |
| Foraker Act | This act set up a new government in Puerto Rico. |
| Open Door Policy | Broke down the spheres of influence in China and showed how the U.S. was becoming more powerful in world affairs. It was created in response to the fact that Americans feared that other nations would prevent them from trading in China. |
| Imperialism | It is the policy of powerful countries that seek control of political and economic affairs of weaker countries and regions. |
| isolationism | Having little to do with political affairs of other nations. |
| Spanish American War | Americans declared war on Spain after the ship Maine exploded. The War was also caused by Americans' desire to expand as well as the harsh treatment that the Spanish had over the Cubans. Furthermore, the U.S. wanted to help Cubans gain independence from Spain. The war resulted in the U.S. gaining Guam and Puerto Rico. |
| Treaty of Paris | Ended the Spanish American war. The U.S. acquired Guam, Puerto Rico, and bought the Philippines for 20 million. |
| Sphere of Influence | Allowed open trade within China. Germany, Britain, France, and Russia and Japan could all trade within China, going into each countries' specific trading area. |
| Roosevelt Corollary | This was an addition to the Monroe Doctrine. In this Roosevelt claimed that the right of the U.S. to interfere in Latin America to preserve law and order. |
| Panama Canal | Was constructed to obtain a quicker route from the Pacific to the Atlantic Ocean. A major problem in building the Canal was caused by the disease that spread through mosquitoes. |
| Dollar Diplomacy | President Taft's policy of encouraging Americans to invest in Latin America. |