Paul Bengston was different from the other boys in the Minnetonka neighborhood where he grew up in the 1960s and early '70s. At age 10, while his pals collected Marvel comic books or chased the latest Roger Maris baseball card, Bengston was searching high and low for pins from Franklin Delano Roosevelt's political campaigns.

The cherished baseball cards probably ended up in Mom's garage sale after his friends left for college. But Bengston's childhood hobby blossomed into what he calls an "adult obsession." Today, he spends nights and weekends tracking down rare treasures to add to his vast collection of political memorabilia, which includes about 30,000 items from 1820 to the present -- with a special focus on Minnesota political history.

To put Bengston's collection in perspective, the Minnesota Historical Society owns about 4,100 political buttons and badges, according to Matt Anderson, a curator there.

Bengston's gems include a button commemorating Teddy Roosevelt's 1910 stop at the Minnesota State Fair, and another marking President William Howard Taft's visit to Shakopee the same year. He owns delegates' badges from the 1892 Republican National Convention in Minneapolis, and a poster from a 1972 fund-raising concert for then-presidential candidate George McGovern. The show featured James Taylor and Barbra Streisand, along with "ushers" like movie stars Raquel Welch and Warren Beatty.

You might think Bengston's kitchen and spare bedrooms are stuffed with Fritz Mondale and Ronald Reagan memorabilia. Not so. His wife Lisa's only rule, he says, is "don't decorate the house" with all the stuff he has accumulated in the last 40 years. He keeps valuable items locked away in safe deposit boxes.

Bengston got his collector's nose from his mother -- a schoolteacher turned homemaker who collected antique combs -- and his love of American history from his father. His collection mania began in 1968, at age 8, when his parents took him to a Waverly, Minn., rally for Hubert Humphrey, that year's Democratic presidential nominee.

"I spent my allowance on two Humphrey buttons, and pinned them to the curtain in my bedroom when I got home," he says. His mother gave him a box of old Eisenhower and Truman buttons, and he bought more items at the State Fair. By summer's end, he had 50 buttons. He was hooked.

Through his college years in Menominee, Wis., Bengston hitchhiked to La Crosse and Eau Claire hoping to "spend his beer money" on buttons he found at weekend flea markets there.

Bengston's parents initially encouraged his hobby as a great way to learn American history. But the lure of a good bargain is part of the appeal, he says. He recalls the first deal he closed, at age 10, at the Hopkins VFW post. "I saw a William McKinley button [president from 1897 to 1901] for 50 cents, and I managed to talk the guy down to 25 cents. When I went home and consulted my book on political buttons' value, I discovered it was worth a whole dollar!"

And then there's the thrill of the chase: "It's not exciting to have a button," Bengston explained, "it's exciting to find a button." Today, he continues to scour flea markets, antique stores and estate sales for rare discoveries.

A particularly fruitful strategy, he says, is to advertise in local papers in the area where an item was originally distributed. His most recent acquisition -- a "Truman for Judge" button from Harry Truman's 1925 judicial campaign -- demonstrates that while success can take time, it is sweet when it comes.

"Three years ago, I advertised for the Truman button in the Independence, Missouri, newspaper," he says. "That's where Truman began his career. I got no response. Then just two weeks ago, I got a call. A woman who owned the button had died, and her children had found my ad clipping in the drawer where she had left it."

Like many, Bengston is excited about the upcoming Republican and Democratic national conventions. He has people working the floors -- not to elect his man but to ferret out hidden campaign collectibles.

Bengston doesn't care about the stuff that everyone will be trying to pin on your lapel. What does he covet most?

"I'd kill for John McCain's or Barack Obama's stage pass," he says.

Katherine Kersten • kkersten@startribune.com Join the conversation at my blog, www.startribune.com/thinkagain.