B. TAYLOR wrote: "I found my great grandfather in Walnut Grove Township as Sam Harris in 1870 census. Later in the 1880 census his name was changed to Crockett Harris. I don't understand the name change..."
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My reply:
This won't help much, but his first name of "Sam" in 1870 could probably have just been his slave name. By 1880, he may have simply exercised his right to choose his own first name of "Crocket".

As far as finding his parents or siblings, that will not be easy. I have the same problem for a couple of my ancestors. I can only surmise by the ages of older persons living nearby who their parents or siblings could have been. I was fortunate enough to have connected with others researching the same ancestors. Good luck!