More states were admitted year after year in the 1840’s: Texas, Florida, and Iowa, and more territory that was not yet incorporated as states was purchased or acquired by treaty. While not states, territories in U.S. possession have governors, use dollars, and their people are U.S. citizens. However those citizens cannot vote in national elections, nor do they have representatives in Congress or the Senate. In 1845 the Oregon Territory was established, which finally gave the U.S. ownership of lands that stretched from sea to shining sea. As with previous areas, this land would then be divided into more states in the following years.
As unclaimed lands in North America began to dwindle, the competition among the resident powers became conflict. In 1846 the U.S. and Mexico entered into a war for control of what is now the American Southwest. After gaining their own independence from Spain, Mexico had originally claimed land from Louisiana all the way to the Pacific Ocean, and the dispute over the border of Texas ignighted a conflict which lasted years. Yet as the war ended the U.S. claimed nearly half of all Mexican territory as their own, from Texas to California. At this point our borders began to closely represent what we know today as the Continental United States.
Less than 15 years later another conflict broke out –this time from within. In 1860 and 1861 eleven states seceded and formed their own nation, the Confederate States of America, based largely on the economic benefits of using slave labor in agriculture. The division ran so deep that Confederate Virginia broke apart, creating the U.S. State of West Virginia from regions that felt that the Confederacy did not represent them. The Union won the Civil War in 1865, but it still took another five years of reconciliation for the 11 states that tried to break free to be re-admitted to the United States.
After the Civil War most new U.S. states were admitted as parts of territories which had not previously been made into states, some taking a long time to earn statehood. Arizona, the 48th state, stood as a territory for nearly 50 years before statehood, and Alaska, purchased from the Russians in 1867, became the 49th state in 1959 after World War II ended. Hawaii, the 50th state and birthplace of President Barack Obama, also gained its statehood in 1959 after playing a critical role in the U.S. efforts in the Pacific Theatre during World War II.