1.25" with covered tin back and vertical pin. Tin carries imprint of St. Louis Button Co. and this was their earliest style back used only 1899-1907. This button may relate to Denison, Iowa or Texas as both states had poll taxes to restrict voting in the 1900s. Cello has pinpoint nick at center and similar even less obvious on extreme left edge but both are exceedingly minor and the button displays glossy and Mint. First we've seen.