Gardner is a city in Johnson County, Kansas, United States. As of the 2010 census, the city population was 19,123.
Gardner was founded where the Santa Fe Trail and the Oregon/California Trails divided. The Santa Fe Trail sent travelers southwest through Sante Fe and Albuquerque toward Los Angeles and San Diego. The Oregon/California Trails bore west for a few miles before turning north toward the Kansas River valley, followed the Big Blue River into present-day Nebraska, followed the Platte River west, and ultimately split in present-day Wyoming, Idaho or Utah.Gardner was founded as a Free-Stater settlement in 1857. Settled primarily by emigrants from Massachusetts, it may have been named for Henry Gardner, then governor of Massachusetts. Four years after its establishment, it became the first community in Johnson County — and perhaps the first in the state — to experience an attack by Confederate forces.The first post office in Gardner was established in 1858