Floyd Risvold was a curious 6-year-old when he found a dusty stamp collection in his grandfather's attic.

That collection became the seed of a passion that grew into a one-of-a-kind collection of historic letters, stamps, maps, documents, photos and books that Risvold studied in the libraries of his Edina home.

Risvold was 97 when he died last year. On Wednesday, the collection he lovingly built over the decades will be auctioned in New York. Experts are drooling over the array of items expected to sell for about $5 million.

"This will be one of the top auctions of the year," said Cheryl Ganz, curator of the Smithsonian National Postal Museum in Washington, D.C. "You're just talking about one rarity after another. ... It just takes your breath away."

Risvold is a legend among philatelists, who collect stamps, postmarks and stamped envelopes, said Charles Shreve, president of Spink Shreves Galleries, which will run the three-day auction.

"He was passionate about history," Shreve said. "He wrapped postal history together with autographed documents and letters to tell a story, the story of the movement west from the Mississippi River in America."

The auction has 1,298 lots, some containing multiple items. They include relics linked to the Pony Express, Indians and Mormons, documents signed by Abraham Lincoln, Thomas Jefferson and John Adams, and items tied to the Minnesota Territory.

A historic treasure trove

Some items are expected to sell for a few hundred dollars. Others, including a 1776 letter from Father Junipero Serra about mail service in what is now San Diego, may sell for hundreds of thousands of dollars. The last Serra letter that came to auction sold for $300,000.

There are treasures like a collection of Civil War diaries, letters, photos, hand-drawn maps and swords owned by a Union soldier and oddities like a signed photo of Sitting Bull.

A horrifying manuscript signed by an interpreter for an 1886 African expedition led by Henry Stanley (of Stanley and Livingstone fame) details his account of "The Jameson Affair," a scandal involving the scion of the Irish whiskey family. James Jameson bought a young girl from a tribe for six white handkerchiefs and gave her to cannibals so he could watch how they killed and ate her. "Mr. Jameson being very much pleased with this sight was making pictures of every act they were doing," the account reads.

A 12-page 1813 letter from Adams to Vice President Elbridge Gerry reflects on his own time as vice president, describing the French Revolution as "a gigantic Infant begotten by Folly, midwifed into the world by Madness, nurtured by Atheism, Deism, and every Species of Vice and Wickedness." Describing his shame at the U.S. House's passage of "Votes of Admiration" for the French, he writes, "When I put the question in Senate, a duty I could not avoid, I felt as if I should sink through the board that supported me."

Adams' letter is expected to bring at least $100,000.

Sixty-six lots have a Minnesota connection. There are letters signed by early governors, a crude map of Fort Snelling, riveting letters from soldiers fighting Indians, and Pierre-Charles LeSueur's 1685 permit to trade with the Sioux. The French fur trader was the first white man to explore the Minnesota River valley.

A pristine 1847 envelope bearing the only 10-cent George Washington stamp known to exist from the Minnesota Territory is expected to sell for $10,000; an 1864 treaty with the Red Lake and Pembina Chippewa signed by Lincoln has an estimated sale price of $5,000.

Risvold waited decades to acquire the items he wanted, Shreve said.

"He researched and put together a hit list of things he knew existed, and over 40 or 50 years he would patiently wait for items to come up for auction," Shreve said.

A lifelong passion

Risvold grew up in the Twin Cities. His daughter, Diane Pearson of Edina, said that at 19, he joined the Coast and Geodetic Survey and roamed the West on horseback, charting the land. Eventually he joined his father's Minneapolis clothing distribution company. At 72, he sold the firm and devoted the rest of his life to the collection, Pearson said.

"That was his passion, besides his family," she said. "He became infatuated with manuscripts that were living history."

Risvold bought his last letter just a few weeks before he died -- a letter he had wanted for 30 years to buy, Pearson said.

It was Risvold's wish that the collection be sold, Pearson said. She said for her, watching the auction company pick up the boxed collection was "like him dying all over again."

But she said her father didn't want his collection "locked up in an institution. He wanted young people to have the joy of collection."

"I want it to go back out to the winds," he told her.

Parts of the collection were displayed in London, San Francisco and Dallas in preparation for the auction. The three-volume, leather-bound auction catalog is a collector's item in itself, Ganz said. The Smithsonian bought a copy for its library. "This will be a reference for years to come," she said.

John Reznikoff, president of University Stamp Company and Archives in Connecticut, said he hasn't been to an auction in years. Last week the document and autograph dealer had the Risvold catalog on his desk.

"A collection like this comes around once in a lifetime," he said. "I'm picking a day and I'm going."

Auction items can be viewed at www.spinkshreves.com.

Mary Jane Smetanka • 612-673-7380