"Historians and archaeologists will one day discover that the ads of our times are the richest and most faithful daily reflections that any society ever made of its entire range of activities," noted that sage student of media Marshall McLuhan. This idea is at the secret heart of the Ad Museum, where so very much of modern American life is caught and preserved with dignity and grace. From the thousands of ways in which the female body has been used to sell products to the ingenuity of the United States military in selling war to the general public, the museum is a treasure trove of American character, creativity, and comedy.

Founded in 1986 by historically minded advertising professionals in Portland, the Ad Museum moved last year to its new space in the city's Chinatown district, three blocks from the lovely Classical Chinese Garden. Bursting with a collection of more than a million items, the museum—the only institution of its kind in the United States—draws between 4,000 and 6,000 patrons a year to the colorful, entertaining room crammed with history and wit. Someday, says curator Catherine Coleman (the smiling young woman who takes your five bucks at the door), the museum would love to expand into the entire block on which it sits.

You'll find the Ad Museum's interactive approach to the icons, slogans, and jingles of mass marketing is both nostalgic and informative.

Visitors will find the museum's interactive approach to the icons, slogans, and jingles of mass marketing both nostalgic and informative. A comprehensive walk-through time line lets you trace the history of advertising in America, beginning with an early newspaper ad (for real estate, in a 1704 Boston News-Letter). From there, you'll see the rise of mail-order catalogs (1876) and celebrity testimonials (1886, actress Lillie Langtry, for soap), the first radio ad (1922, also for real estate), and finally the start of television advertising (1939, during a Brooklyn Dodgers broadcast, again for soap).

Poke your head into a studio for a look back at classic American television commercials from 1950 to 1970, starring such well-known pitchmen as Mr. Clean. Along the way, you'll pick up copious amounts of advertising trivia, such as the fact that Planters' Mr. Peanut was the brainchild of a 13-year-old boy and that Mobil's flying Pegasus originally took wing in South Africa. There are also print and television exhibits featuring award-winning ads from the annual Cannes International Advertising Festival, which include hilarious, poignant, and riveting spots from Brazil, Australia, Spain, England, Norway, Canada, France, Germany, and the Netherlands.

Things begin to get serious when you approach Twenty Ads That Shook the World. This exhibit offers some startlingly honest discussions of how Marlboro used the cowboy mythos to hawk cigarettes, Absolut resorted to selling the shape of its bottle, Coca-Cola allied itself with Santa Claus, Listerine sold the battle against bad breath, Clairol successfully marketed a dangerous product (hair coloring), and Republican candidate Barry Goldwater was hammered by a seemingly innocuous 60-second television spot during his 1964 bid for the presidency. One comes away with an appreciation of the power these images have had to effectively cut through the daily bombardment of media hype and deliver their messages to us.

Coleman dreams curatorially of showing more of the vast collection at once. For now, though, the museum is open four days a week (Wednesday through Saturday), rents out traveling exhibits (like Dream Girls: Images of Women in Advertising, which went to Chicago and New York, among other cities), and draws patrons, fans, and scholars via the Net. It also hosts tours, sells all sorts of peculiar ad-inspired products (need a Spam T-shirt?), and is always, notes the cheerful Coleman, interested in donations and loans of advertising-related collections and treasures. Who knows? Maybe the Budweiser frogs are out there waiting to join the party.