I am interested in this Agnew family as well. I am compiling data pretaining to slaves in ante-bellum Tippah County. I am descended from Rogan, Boyd, and Williams slaves. I expanded my research to include the whole county and found a wealth of info so far. Having correct genealogical info. on the free white families helps tremendously...thank you so much for starting this wonderful thread.
For anyone interested, many of the slaves mentioned in the diary show up not only in the 1870 census, but also in a Freedmen's Labor contract for work with Dr. E. Agnew (1865). I have created a website for slave-specific info. Dr. Agnew's "plantation"page is here http://www.rootsweb.com/~afamerpl/plantations_usa/MS/agnew.htmlhttp://www.rootsweb.com/~afamerpl/plantations_usa/MS/agnew.html