An 1860 Lincoln and Hamblin campaign flag is valued at $20,000-35,000 ahead of a sale at Hake's Americana on July 12-14.
The piece is in a remarkable state of preservation considering its great age.
Lincoln campaign flags are hugely popular collectors' items
Campaign flags were popular pieces of political ephemera that largely disappeared with the arrival of the badge button in the early 1900s.
Alex Winter, president of Hake's, comments: "Abraham Lincoln parade flags consistently rank among the most coveted items by political memorabilia collectors, and an example like the Lincoln/Hamlin flag entered in our July sale would be considered a milestone acquisition for even the most advanced collection.
"In our March auction, a very rare 1864 Lincoln and Johnson parade flag sold for nearly $24,000. The 1860 flag differs in that it is larger and from an earlier campaign.
"It's in beautiful condition - truly deserving of the description 'investment grade'".
Another example sold for $26,290 at Heritage Auctions in 2010.
The typically eclectic auction will also feature a rare 1936 Berlin Olympics silver medal.
The lot is expected to make $5,000-20,000.
It's one of only 320 medals struck for the tournament, which took place in Nazi Germany just three before the outbreak of the second world war.
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