| Term | Definition |
| Robert S. Neighbors | U.S. Indian Agent who disagreed with federal policy |
| Winfield Scott | U.S. General who captured Mexico City |
| Alabama-Coushatta | Indians whose right to remain in Texas was recognized by the state government |
| John Coffee Hays | famous Texas Ranger who fought in the Mexican American War |
| Nicholas Trist | U.S. diplomat who negotiated the Treaty of Guadalupe Hidalgo |
| Mexican Cession | territory in northern Mexico that was ceded to the United States |
| Zachary Taylor | commander of U.S. forces in Texas when the Mexican War began |
| Compromise of 1850 | agreement under which Texas gave up land claims in New Mexico |
| Henry Clay | Kentucky politician and author of the Compromise of 1850 |
| offensive | a major troop advance |
| Texas Rangers | "Rip Ford" and John Coffee Hays were well-known members of this group |
| Santa Anna | head of Mexican forces during the Mexican War |
| Rio Grande | the first action of the war took place when Mexican troops crossed over this and attacked U.S. troops |
| California & New Mexico | Mexican territory captured by the U.S. in fighting out west |
| Mexico City | the war was ended with the capture of this |
| Colt Six-Shooter | gave the Texas Rangers a powerful advantage in battle against the Comanche & Kiowa |
| reservations | land set aside for Indians |
| James K. Polk | ordered General Zachary Taylor and thousands of troops into Texas |
| Juan Seguin | Texas Revolution veteran and former mayor of San Antonio who fled Texas before the war, fearing for his life, was forced to serve in the Mexican army |
| Nueces River | Mexico believed that this separated Mexico and Texas |
| Monterrey | General Scott's strategy involved landing soldiers at this location and marching them inland towards Mexico City |
| disease | this factor killed most U.S. soldiers lost in the Mexican War |
| Ft. Worth | abandoned by the army after settlers moved past it, deeper into the frontier |
| slavery | many southerners moved here with these causing the African American population in Texas to grow during the 1850s |