convey in these pictures? >> i think after emancipation, after 1863 and the emancipation proclamation, the pictures were a way of reaffirming that freedom and the sense of dignity and humanity that accompanied freedom. >> reporter: more than 1,000 of the photos were discovered in archives and libraries across the country, like here at the schomburg research center in harlem, where a dozen of them are on display to mark the proclamation's anniversary. the photographs are also part of a new book cowritten by krauthammer called "envisioning emancipation." >> i think the legacy of the emancipation proclamation gave every african-american person a sense of hope and a sense of inspiration. >> reporter: what was it about posing in uniform? >> well, look at them. they're so dignified. they're the epitome of manhood, of patriotism, of honor. there really was a sense that they were fighting for their people and for their nation.