Carte-de-visite of James Law (1838-1921), first veterinary professor at an American university, by Purdy & Frear.

Cyanotype, Camp F.L. Guenther, U.S. Coast Artillery at the Pan-American Exposition, Buffalo, New York, 1901.

A proud mother responded to news service’s request for a photograph of her physicist-son killed during World War I.

Drawing of "Neptune Baird," dog belonging to Spencer Fullerton Baird, second Secretary of the Smithsonian Institution, circa 1840s.

Cyanotype, disassembled mannequins in Post Office Department exhibit at Cotton States Exposition, Atlanta, 1895.

Cyanotype, Department of Agriculture exhibit at the Pan-American Exposition, Buffalo, New York, 1901.

A 1936 exchange of letters about the prickly porcupine preserves both a contemporary scientific debate and the wit and wisdom of a young Utah girl with a beloved pet.

The Smithsonian Institution Archives continually strives to add more collection information to its website. This is a periodic post highlighting new acquisitions and individual collection items.

U.S. Capitol building as seen from the tower of the Smithsonian Institution Building, or Castle, with Baltimore and Potomac railroad station and tracks in view, circa 1880, SIA RU000095, SA-197.

To celebrate National Dental Hygiene Month, the Smithsonian Institution Archives presents photographs of dentists and dental researchers.