Button help!!!

[Blind Squirrel]

A fellow detectorist found this in SC. Any ideas?

 

[Dig em all]

http://www.relicman.com/buttons/B4096.htm

 

[TheCannonballGuy]

The button's emblem complies with the US Army's regulation of 1832 for Army General Staff Officer buttons. Unfortunately for us civil war relic hunters, that particular emblem was in use from 1832 to 1902. Fortunately, various manufacturers of the buttons produced several minor vartiations in the emblem (and the button's flat rim), which can enable us to time-date the specific button.

By extra-carefully observing the button's minor details in the photo you posted, I see that:
Your fellow-detectorist's button's eagle holds 4 arrows in its right talons. Just below the shield's base, the eagle has 2 v-shaped rows of feathers above its spread tailfeathers. The shield has 3 sharp-pointed corners, and a perfectly-flat top. So, if the eagle is surrounded by 24 stars, your button is shown in the Albert button-book as GS-13E. As shown in the book's photo, GS-13E has an extra-wide rim, which almost always means post-1865 manufacture. Because one of the (only two) backmarks listed for GS-13E went out of the button-supplying business in 1880, there's a pretty good chance your fellow detectorist's post-1865 button that was dug in South Carolina was worn by a yankee officer during the postwar Reconstruction/Occupation period (1866-to-mid-1870s) in that state.