Green County was formed from Glasgow County in 1799. It was a name change from Glasgow to Greene. Researchers may want to look for Wayne and Glasgow counties when researching family history prior to 1799.
This county has seen many border changes over the years that researchers should be aware. See The Formation of the North Carolina Counties, 1663-1943, by David Leroy Corbitt for a complete history of the county formation. (Affiliate Link)