The abolitionists prevailed, and on January 29, 1861, Kansas entered the Union as a free state.After the Civil War, the population of Kansas grew rapidly when waves of immigrants turned the prairie into farmland.Directly presaging the American Civil War, these forces collided, entering into skirmishes that earned the territory the name of Bleeding Kansas.

Southwest Kansas, however, was still a part of Spain, Mexico, and the Republic of Texas until the conclusion of the Mexican–American War in 1848, when these lands were ceded to the United States.

From 1812 to 1821, Kansas was part of the Missouri Territory.

By 2015, Kansas was one of the most productive agricultural states, producing high yields of wheat, corn, sorghum, and soybeans.) is the 15th-largest state by area and is the 34th most-populous of the 50 states with a population of 2,911,641. Mount Sunflower is Kansas' highest point at 4,041 feet (1,232 m).

For a millennium, the land that is currently Kansas was inhabited by Native Americans.

Many African Americans also looked to Kansas as the land of "John Brown" and, led by freedmen like Benjamin "Pap" Singleton, began establishing black colonies in the state.

Leaving southern states in the late 1870s because of increasing discrimination, they became known as Exodusters.

The geographic center of the 48 contiguous states is in Smith County near Lebanon.

Until 1989, the Meades Ranch Triangulation Station in Osborne County was the geodetic center of North America: the central reference point for all maps of North America.

The first European to set foot in present-day Kansas was the Spanish conquistador Francisco Vázquez de Coronado, who explored the area in 1541.

In 1803, most of modern Kansas was acquired by the United States as part of the Louisiana Purchase.

At the same time, the Chisholm Trail was opened and the Wild West-era commenced in Kansas.