A Minnesota man plans to sell an extensive, $2.5 million collection of Uncle Sam memorabilia, described as the nation’s most valuable, at an auction this week in Fairfield.

The two-day event starting Friday will include 2,000 items, such as posters, toys, political buttons, advertisements and original artwork by James Montgomery Flagg.

Flagg dressed in a distinctive red, white and blue uniform and painted a self-portrait that became the basis for the first Uncle Sam posters and images that followed.

In 1917, Flagg created the famous “I Want You for the U.S. Army” recruitment poster.

Gerald Czulewicz of Isanti, Minn., who started his collection 40 years ago, wanted to sell it to Troy, N.Y., which bills itself as the home of Uncle Sam. But the city didn’t have the money and the sale didn’t work out.

The collection was featured in a national tour of 27 museums in 16 states from 1980 to 1992.

“It’s the most significant collection of Uncle Sam memorabilia ever auctioned and it is the largest,” said James Julia, the auctioneer who is handling the bidding at his company’s Fairfield facilities.

Perhaps the rarest and most valuable item in the collection is the only known photographic image of Sam Wilson of Troy, N.Y., who supplied beef to the U.S. Army during the War of 1812.

Wilson’s casks of beef were stamped “U.S.,” and according to legend, handlers of the casks began referring to them as “Uncle Sam’s beef.” By an act of Congress in 1961, Wilson was declared to be the source of the familiar image of Uncle Sam.

A pre-auction estimate of a tintype of Wilson has been pegged at $15,000 to $20,000, according to the Julia auction catalog.

Czulewicz, an art and antiques dealer, became interested in Uncle Sam lore when he was 12 and his brother was serving in the Korean War. His first Uncle Sam purchase was a songbook he bought in an antique bookstore in his hometown of Erie, Pa., in the 1960s.

The songbook will not be part of the auction.

“I’m going to keep it for myself,” said Czulewicz, who will not be attending the auction.

“I couldn’t take it. It would be emotionally just too much for me,” Czulewicz said.