It's relatively rare for a photograph to be valued for a huge sum of money--few single photos have ever sold for more than $1 million.
So there must be something special about a photo book of images of the Mississippi River during the 1880s, captured by photographer Henry Peter Bosse, which Sotheby's just valued at $4.5 million, according to the Star Tribune (via Newser).
Bosse was hired to chart the Mississippi for the Army Corps of Engineers in the 1870s, when the river was considered to be the lifeline of the country.
According to the Tribune, as he worked, "Bosse dragged along his large 11-by-14 camera, composing shots of bridges and scenery, often keeping his lens open so long -- to capture adequate light -- that the river's movements were blurred."
Bosse died in 1903, the victim of food poisoning by a bad meal of canned asparagus prepared by his wife.
But one of his many photo albums took on a life of its own. It spent more than five decades floating on a dredge, sitting on the desk of the captain. It wasn't until 1989 that the Army Corps of Engineers realized the value of the book and placed it in a vault in the U.S. Bank in St. Paul, Minnesota, according to the Tribune.
The album is currently being considered for preservation by the Minnesota Historical Society, which is why Sotheby's appraisers were called in.