The Convention & Visitor's Bureau reminds us that Geary County is named for John Geary: A Key Figure in the History of the Kansas Territory:
John White Geary served as the third Territorial Governor of Kansas during a tumultuous period with his time in office was marked by attempts to bring order to "Bleeding Kansas," a time of intense conflict over the issue of slavery.
He was a man of diverse background, also having been a mayor of San Francisco, a Union general in the Civil War, and a governor of Pennsylvania.
The county was named after Geary in the 1880's. Before that it was called Davis County and was named after former U.S. Secretary of State and later the Confederate president, Jefferson Davis.