This is a Cabinet Card, which was a popular photo format in the 1880s. They were first used in the 1860s for landscape views, eventually adapted to portraits, and had greatly declined by the 1890s.

Standard-size Cabinet Card, measuring about 4.5 x 6.5 inches.

Photographed by T. W. M. Havee in Stamford, Connecticut.

Will be shipped safely and securely! All of my paper items are protected in archival-safe polypropylene sleeves and packaged in rigged cardboard.