"This is a unique conjunction of historical material with the popular zeitgeist," said Selby Kiffer, the auction house's expert on books and manuscripts. "I have not experienced anything like this before."
Alexander Hamilton's letters to be auctioned in NYC →
The copy was one of 48 signed by Lincoln and printed to raise money for medical care for union soldiers, Kiffer said.
RFK-owned Emancipation Proclamation up for auction →