Captain F.B.S. (Fred) Cocke's company is mentioned in several places. Not sure if my ancestor (Elihu L. Kirksey) was present for the battle, but I like to imagine that he was.
Frederick Bird Smith Cocke, Jr. was born in Tennessee in 1839, one of 15 children of F.B.S. Cocke, Sr. and Eliza Malvina Rogers. There is an article about F.B.S., Sr. in the Handbook of Texas Online. http://www.tshaonline.org/handbook/online/articles/CC/fcolc.html The article states that this F.B.S. Cocke enlisted as a private in the Helena Guards in 1861 (at age 48) and then served as a Captain under Slaughter at Palmito Ranch, meanwhile serving as a Texas Legislator from 1862-1863. The author has obviously erroneously combined father and son (who share the same name) into one person. I know that the senior Cocke was not the leader of this company. Capt. Fred Cocke gives testimony on behalf of one of his men, Ben M. Roberts, in Roberts' 1909 pension application. Cocke states that his is 70 years old, and his father had already died by this time.
I found a Cocke genealogy reference showing this family. http://archiver.rootsweb.ancestry.com/th/read/COCKE/2000-04/0955905227
I believe that this same Fred Cocke later became District Attorney in Bexar County. http://www.co.bexar.tx.us/commct/cmpct4/History/Elected_Officials/District_Attorneys/district_attorneys.htm He was the prosecutor in the murder trial of Ben Thompson for the killing of Jack Harris in San Antonio in 1881. http://frontiertimesmagazine.com/1226.html
Sometime later, Captain Cocke himself served in the legislature. He was responsible for introducing the bill that established Southwest Texas State Normal School in San Marcos, now Texas State University. http://ecommons.txstate.edu/cgi/viewcontent.cgi?article=1002&context=jamcfacp
His daughter, Kate, married Roy C. Archer, who later became Chief Justice of the Texas Court of Appeals.