This post from the Library of Congress discusses the acquisition and digitization of an album containing 48 rare photographs dating to the 1860s, including a previously unrecorded portrait of Harriet Tubman and images of other African American leaders. It is an amazing public record of abolitionists, public educators, and even contains the only known photograph of John Willis Menard, the first African-American man elected to the U.S. Congress. The full collection is now available online.