I searched through the Albert button-book's photos of South Carolina State Militia buttons, to find its Albert button-number and thus its backmark and time-period for you.
It is definitely Albert's button SC-8A, and it was manufactured sometime between 1830 and 1858, by the firm of Young, Smith & Co. of New York City. Being made years before the war, it most likely would have been worn by a member of a pre-war SC Militia regiment, rather than a wartime volunteer or draftee. Apparently, it was lost fairly early during the war, because so little of its gold gilt has been worn off.
Your North Carolina State Militia button is a wartime Confederate-made one, which Albert calls a "CS Local" (a somewhat confusing term, meaning, locally-made in the Confederacy, not by a Northern firm or British maker). Most "local" NC buttons have a rather crude die-stamped emblem, showing weak detailing, and do not have a backmark. I can't quite tell for certain whether your button is Albert's NC-8A, B, C, or D. The head on the figure at right makes it look like NC-8A, and if so it should have an "S.A. Myers / Richmond Va" backmark. But it could have a "W.Wildt & Son / Richmond Va" backmark.