I believe this refers to Perkin's Regiment Cavalry of the Missouri State Guard. Co D was made up of men mostly from Audrain Co. Missouri and apparently the majority of those became members of the 9th Missouri Volunteer Infantry CSA. Lt. Col. Caleb J/I Perkins is listed as the commanding officer. At least one listing refers to Perkins Battalion of the 9th.
Scouring the SOS records it appears that the vast majority of those individuals that surrendered in 1865 at New Orleans and paroled at Alexandria LA on June 7th 1865 were from Boone,Calloway, and Audrain Counties in Missouri.
Samuel B Gibson was born and died in Boone Co. MO.
Samuel H or S.H. Gibson of Quantrill's Regiment was raised in Jackson County MO, later lived in Boone County as well.
There is a Samuel(Samual) Gibson who located to Empire Twshp, Stanislaus Co., California after 1860 born abt 1835. Married a Mexican by the named of Talodo and had two sons James and Richard. Quite wealthy in 1870 census with land holdings listed as worth $10,000.00 Father born in KY, Mom in Ohio.