Hi Zenoba, I did find Pleas/Kit in both 1870 and 1880, which you have. I can't find him in 1900 and he may have been deceased by then. I checked Noxubee County, MS records [at least what I could find online] and there was nothing for the Shanklins. Try requesting some lookups from volunteers at this link for Noxubee County: http://www.rootsweb.ancestry.com/~msnoxube/lookups2.htmlhttp://www.rootsweb.ancestry.com/~msnoxube/lookups2.html
Now, as far as siblings for Kit, I am really thinking that Henry b. about 1842 and Sylvester, b. about 1846, are siblings of Pleas/Kit. From the 1870, it looks like Kelley b. 1862, and James 1866, are the children of Kit and Patience. In 1880, Littie b. 1872 is a daughter of Kit, also. There is a 20 year span between Kelley and Henry!Henry and Sylvester seem to be too close to the age of Kit to be his sons, as Kit was born in 1830 and would have only been 12 when Henry was born in 1842. Kit would have only been 16 when Sylvester was born.
In one of your other messages you mentioned other Shanklins from Noxubee County and wondered who they were. Based on births of the children of Morris and Susan; Arnold and Ann Shanklin; it appears these folks came to MS immediately following the Civil War. Arnold and Ann have a daughter, Caroline born 1863 in NC and her sister Harriet, born 1865 in MS. Morris was born in 1837 and Arnold in 1845. Are these brothers of Kit? Or did they all take the surname of Shanklin and are unrelated? From the 1860 census, there were only two places in North Carolina I could find Shanklins holding slaves with a male aged 30: Orange County [Lydia Shanklin] and Hyde County [A. Shanklin]. Maybe you could begin there looking for records? You might try the LDS church; they would probably have a nearby family history center to your home? They have copied a lot of records from all over the world and you can borrow them for a fee from your local family history center. The LDS catalogue is online: http://www.familysearch.org/eng/default.asphttp://www.familysearch.org/eng/default.asp
I am sure you could also borrow Noxubee County, MS records from them, as well. Don't forget to look for alternate spellings of Shanklin; I have been finding Shankland, Shunklin, etc. Ancestry has a soundex feature that will help with the various spellings, click on the box and it will give you many variants of the Shanklin name.
I would advise reading a book on African American genealogy. I have found that genealogy guides are very helpful in explaining the ins and outs of research in various areas of the author's expertise. They will know what types of records are available for various areas and time frames and where to find them. I wish I could have found more for you! Good Luck, Barbara