This is the first button distributed in all federal penitentiaries after the standardization of staff uniforms. It was introduced in the summer of 1896 and was produced both in brass (gilt) and white (silver) metal. Surviving records seems to indicate that the brass (gilt) versions were used by the Keepers and their superiors. The white (silver) metal versions were worn by the junior or ‘guard’ ranks. At some point, this distinction may have been reversed. Research is ongoing. This example is in white (silver) metal. The back mark reads ‘THOMAS CARLYLE, ASTON, BIRMINGHAM, ENGLAND’.