During the second half of the nineteenth century, America became a continental empire. Between 1850 and 1912, seventeen new western states joined the Union, completing the formation of the contiguous United States. Hundreds of thousands of settlers flocked to these new regions, shifting the center of the country's population dramatically toward the West. The federal government facilitated this western movement in several ways. Most critically, in 1862, Congress passed the Homestead Act, the Pacific Railways Act, and the Morrill Education Act. All three used public lands to achieve national goals: western migration, the construction of a transcontinental railroad, and the development of state colleges.
The addition of these western territories and their integration within a national economy added enormously to the wealth and power of the United States. In addition, the "Wild West" and the "winning of the West" provided important themes to American culture. In 1890, an American census report declared the West "closed." Yet in the years that followed, the West assumed an even more prominent place within American culture. The mythology surrounding the West's homesteading pioneers, political heroes, and frontier clashes grew more elaborate. Similarly, efforts to preserve the West's natural conditions increased. The Sierra Club was formed in 1892 to protect America's wilderness areas. The National Park Service was created in 1916 to manage the nation's parks and ensure that they be left "unimpaired for the enjoyment of future generations."
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