Olathe was incorporated in 1857, and while not the first city in Johnson County, its rapid growth led to it being named the county seat in October 1859. Rising tensions across the nation over the issue of slavery led to numerous clashes between abolitionists settlers and neighboring slave state Missouri. These clashes further escalated and become a part of the greater conflict known as Bleeding Kansas. With the admission of Kansas into the Union as a free state in 1861, violence began to dissipate. Peace, however, continued to elude Olathe for many years to come. In 1861, Union officials and local military forces created a military post in the city. It housed one company of troops along with the local militia.