Most American settlers traveling west to Oregon, Deseret, or California avoided the rugged Rocky Mountains and instead followed the North Platte River and Sweetwater River through what is now Wyoming. On 1851-04-09, Hispanic settlers from Taos, New Mexico, settled the village of San Luis, then in the New Mexico Territory, but now Colorado's first permanent European settlement. Gold was discovered along the South Platte River in western Kansas Territory in July 1858, precipitating the Pike's Peak Gold Rush. The placer gold deposits along the rivers and streams of the region rapidly played out, but miners soon discovered far more valuable seams of hard rock gold, silver, and other minerals in the nearby mountains.
The Provisional Government of the Territory of Jefferson was organized on 1859-10-24, but the new territory failed to secure federal sanction. The election of Abraham Lincoln for U.S. President on 1860-11-06, led to the secession of six slave states and the threat of civil war. Seeking to augment the political power of the free states, the Republican led U.S. Congress hurriedly admitted the eastern portion of the Territory of Kansas to the Union as the free State of Kansas on 1861-01-29, leaving the western portion of the territory, and its gold fields, unorganized.
Thirty days later on 1861-02-28, outgoing U.S. President James Buchanan signed an act of Congress organizing the free Territory of Colorado. The original boundaries of Colorado remain unchanged today. The name Colorado was chosen because it was commonly believed that the Colorado River originated in the territory. Early Spanish explorers named the river the Rio Colorado for the reddish-brown silt the river carried from the mountains. In fact, the Colorado River did not flow through the State of Colorado until House Joint Resolution 460 of the 66th United States Congress changed the name of the Grand River to the Colorado River on 1921-07-25.
The United States Congress passed an enabling act on 1875-03-03, specifying the requirements for the Territory of Colorado to become a state. On 1876-08-01 (28 days after the Centennial of the United States), U.S. President Ulysses S. Grant signed a proclamation admitting the State of Colorado to the Union as the 38th state and earning it the moniker "Centennial State". The discovery of a major silver lode near Leadville in 1878, triggered the Colorado Silver Boom. The Sherman Silver Purchase Act of 1890 envigorated silver mining, but the repeal of the act in 1893 led to a major collapse of the mining and agricultural economy of the state.
Colorado women were granted the right to vote beginning on 1893-11-07, making Colorado the first U.S. state to grant universal suffrage by popular vote. By the 1930 U.S. Census, the population of Colorado exceeded one million residents. The state suffered through the Great Depression and the Dust Bowl of the 1930s, but a major wave of immigration following World War II boosted Colorado's fortune. Tourism became a mainstay of the state economy, and high technology became an important economic engine. Colorado's population exceeded 4.3 million at U.S. Census 2000.
Three warships of the United States Navy have been named USS Colorado. The first USS Colorado was named for the Colorado River. The later two ships were named in honor of the landlocked state.
The state's most populous city, and capital, is Denver. The Denver-Aurora-Boulder Combined Statistical Area, home to 2,927,911 people, contains more than two-thirds of the state's population. Residents of Colorado are properly referred to as Coloradans, although the term Coloradoans is still used.
As of 2005, Colorado has an estimated population of 4,665,177, which is an increase of 63,356, or 1.4%, from the prior year and an increase of 363,162, or 8.4%, since the year 2000. This includes a natural increase since the last census of 205,321 people (that is 353,091 births minus 147,770 deaths) and an increase due to net migration of 159,957 people into the state. Immigration from outside the United States resulted in a net increase of 112,217 people, and migration within the country produced a net increase of 47,740 people.
The largest increases are expected in the Front Range Urban Corridor, especially in the Denver metropolitan area. The state's fastest growing counties are Douglas and Park. Both counties had been suburbanized or grew by 5 times in population in the 1990s and early 2000s. Large numbers of new residents in the state originate from California, which led some locals to feel that their state was "Californicated" in the 1990s (esp. Denver resembled more of Los Angeles) when real estate home prices, lower cost of living and a healthier economy in growth rates drew in over 100,000 Californians at the time, and there are others moved in from East Coast states. The center of population of Colorado is located just north of the town of Critchell in Jefferson County.
Colorado has one of the highest proportions of Hispanic citizens of any U.S. state; only five states have a higher percentage. Denver and some other areas have significant Mexican populations, while southern Colorado has a large number of Hispanos, the descendants of early New Mexican settlers of colonial Spanish origin. The 2000 U.S. Census reports that 10.52% of people aged 5 and over in Colorado speak Spanish at home. Colorado, like New Mexico, is very rich in archaic Spanish idioms.
Colorado has a history of African-Americans communities which are located in northeast Denver in the Montbello, Green Valley Ranch, Park Hill and Colfax Park areas. The state has sizable numbers of Asian-Americans of Chinese, Filipino, Korean, Southeast Asian and Japanese descent. The Denver metropolitan area is considered more liberal and diverse than much of the state when it comes to political issues and environmental concerns, as the Denver area rapidly grows in size, sprawl and population in the last 40 years.
According to the 2000 Census, the largest ancestry groups in Colorado are German (22%) including of Swiss and Austrian nationalities, Irish (12.2%), and English (12%). Persons reporting German ancestry are the largest group in the state and are especially strong in the Front Range, the Rockies (west-central counties) and Eastern parts/High Plains. Denver and nearby areas on the Front Range has sizable Scandinavian, Italian, Slavic and Jewish American communities, partly a legacyof gold