For millennia, the land that is presently Kansas was inhabited by Native Americans. Francisco Vásquez de Coronado was the first European to set foot in present-day Kansas, exploring the area in 1541. In 1803, most of Kansas was secured by the United States as part of the Louisiana Purchase. Southwest Kansas, however, was still a part of Spain, Mexico, and the Republic of Texas until the conclusion of the Mexican-American War. From 1812 to 1821, Kansas was part of the Missouri Territory. The Santa Fe Trail traversed Kansas from 1821 to 1880, transporting manufactured goods from Missouri and silver and furs from Santa Fe, New Mexico. Wagon ruts from the trail are still visible today.
In 1827, Fort Leavenworth became the first permanent settlement of white Americans in the future state. The Kansas-Nebraska Act became law on May 30, 1854, establishing the U.S. territories of Nebraska and Kansas. Kansas Territory stretched all the way to the Continental Divide and included the sites of present-day Denver, Colorado Springs, and Pueblo.

Some of the first Americans to settle in Kansas Territory were abolitionists from Massachusetts and other Free-Staters, who attempted to stop the spread of slavery from neighboring Missouri. Missouri and Arkansas sent settlers into Southeastern Kansas, namely Crawford County, Bourbon County, and Cherokee County, who attempted to sway votes in favor of slavery. Directly presaging the American Civil War, these forces collided, entering into skirmishes that earned the territory the name of Bleeding Kansas. Kansas was admitted to the United States as a free state on January 29, 1861, making it the 34th state to enter the Union. By that time the violence in Kansas had largely subsided. However, during the Civil War, on August 21, 1863, William Quantrill led several hundred men on a raid into Lawrence, destroying much of the city and killing nearly two hundred people. Until the 1995 bombing of the Alfred P. Murrah Federal Building in Oklahoma City, Oklahoma, Quantrill's raid was the single bloodiest act of domestic terrorism in America.
After the Civil War, many veterans constructed homesteads in Kansas. Many African Americans also looked to Kansas as the land of "John Brown" and led by men like Benjamin "Pap" Singleton began establishing black colonies in the state. At the same time, the Chisholm Trail was opened and the Wild West era commenced in Kansas. Wild Bill Hickok was a deputy marshal at Fort Riley and a marshal at Hays and Abilene. Dodge City was another wild cowboy town in the late 19th century. In one year alone, 8 million head of cattle from Texas boarded trains in Dodge City bound for the East, earning Dodge the nickname "Queen of the Cowtowns." Bat Masterson and Wyatt Earp were both lawmen in Dodge City. In part as a response to the violence perpetrated by cowboys, on February 19, 1881, Kansas became the first U.S. state to prohibit all alcoholic beverages.
As of 2005, Kansas has an estimated population of 2,744,687, which is an increase of 10,990, or 0.4%, from the prior year and an increase of 55,863, or 2.1%, since the year 2000. This includes a natural increase since the last census of 76,138 people (that is 204,663 births minus 128,525 deaths) and a decrease due to net migration of 19,541 people out of the state. Immigration from outside the United States resulted in a net increase of 38,222 people, and migration within the country produced a net loss of 57,763 people.
The center of population of Kansas is located in Chase County, in the community of Strong City.
The largest reported ancestries in the state are: German (25.9%), Irish (11.5%), English (10.8%), American (8.8%), French (3.1%), and Swedish (2.4%).
