Images courtesy of Legend Numismatics

The history of this coin:
PCGS Proof-58 (illustrated above).  Ex - Captain John W. Haseltine - Phineas Adams (for whom this coin is named) - Henry Ahlborn - John P. Lyman - Waldo Newcomer (via S. Hudson Chapman) - B. Max Mehl (on consignment) - Colonel Edward H.R. Green - Col. Green estate - A.J. Allen - F.C.C. Boyd - Abe Kosoff and Abner Kreisberg (on consignment) - Percy A. Smith - B. Max Mehl - Amon Carter - Stack's "Carter" - L.R. French, Jr. (via John Rowe III) - Stack's auction - The Rarities Group - National Gold Exchange - Heritage Rare Coin Galleries - David Liljestrand - Midwest collection - National Gold Exchange, Kenneth Goldman, and Anthony Terranova - Legend Numismatics - Phillip Flanagan - B&M 11/2001, $874,000 - Donald H. Kagin and The Rarities Group - offered by Kagin's in the January 7, 2002 issue of Coin World for $1,100,000.00 - B&M "ANA Sale" 07/2003, $1,207,500.00 - Kevin Lipton

Notes:
This example is of the "Class III" variety, indicating that it was made sometime in (or after) 1858.

Sources and/or recommended reading:
Kagin's advertisement, COIN WORLD, January 7, 2002