The Frank Headrick referred to in the 1889 Goodspeed's book "History of Laclede, Camden, Dallas, Webster, Wright, Texas, Pulaski, Phelps and Dent Counties, Missouri" was from another Headrick family that lived in the exact same places as Casper's family. Frank's brother, Silas J. Headrick was mentioned in that book also. I have never seen anyone identify exactly how these two families- Casper and Christopher Headrick- were linked but they were cousins of some sort. Frank's father was Christopher Headrick b. 1799 in Davidson, NC. Frank, or Franklin Headrick, was born 16/22/1828 in Davidson County, NC. His brothers were Silas J. Headrick b. 1831 in NC, James Adison Headrick b. 1825 in NC, and Frederick Headrick b. 1833 in NC. They came to Watkins township, Anutt, Dent County, Missouri around 1835 and were some of the first settlers in this area. They lived there the rest of their lives and still have descendants there.
Frank was a Confederate Captain in the 9th Battalion Pindall's Sharpshooters Company C and was at the battles of Helena, Pleasant Hill, Jenkin's Ferry and surrendered at Shreveport, LA in 1865. His brother Silas was a Confederate 2nd Lt. in that same outfit. I also have them listed in the Confederate 10th Missouri Infantry.
According to ancestry.com there is another completely different Casper Headrick b. 1823 in Georgia on their "Civil War Draft Records". He is listed as being from Bolinger County, Missouri at the time of this Civil War registration.
I hope this helped sort out the 2 different men named Casper Headrick.