During the Civil War, Coldwater Grove existed 13½ miles east of Paola, Kansas. It straddled the Kansas-Missouri border, being partly in both states. About June 1863 a Union military post was established on the Kansas side of the community and the post was put under the command of Lt. Col. Charles S. Clark. Clark also commanded four nearby posts. Guerrillas were apparently still active in May 1865. Capt. A. J. Lumsden wrote in a report the troops from Colwater Grove killed one. The last known report concerning the post was dated June 3, 1865.