The following is from the regimental history of the Second Kansas Cavalry:
"On the 26th of December, to the five squadrons as above organized, the Governor attached four companies of Nugent's Regiment of Missouri Home Guards, as follows: F. company, Capt. A. Thomas; G company, Captain C. Lovejoy; H company, Captain B. F. Simpson, and I company, Captain C. Hill. (These four companies were organized in the fall of 1861, in the counties of Douglas, Johnson, and Miami, under command of Lieutenant Colonel William Mewhinney, of Douglas county, and attached themselves temporarily to Nugent's regiment. They were raised for home service, and were consequently disbanded on the 4th of February, 1862), and the organization then consisting of nine companies, was designated by order of the Governor the Ninth Kansas Volunteers."
http://www.kansasguardmuseum.org/2ksvls.html

Nugent's regiment wasn't disbanded until sometime in early 1862. Among its previous actions was to accompany Fremont on his pursuit of Price in October 1861.