Four buttons from a Pullman Porter uniform

Four (4) round, silver colored Pullman Porter buttons that may have originally been sewn to a Porter uniform. The buttons contain the word "PULLMAN" at the center on the front. The back of the buttons have a small circular piece of metal attached to the center, which was probably used to attach the button to the uniform. Also on the back is the following information: "SCOVILL MFG. CO/WATERBURY".