A tour connected to the National World War II Museum is taking three dozen people to the battlefields and towns in Belgium where the Battle of the Bulge was fought 70 years ago.

The Battle of the Bulge is famous for an incident in which the Germans demanded that U.S. forces surrender. The demand was made three days before Christmas in 1944 after the Germans surrounded the 101st Airborne Division in the town of Bastogne. U.S. Gen. Anthony McAuliffe sent back a one-word reply to the Nazis: "Nuts!" [pullquote]

The Germans initially did not know what to make of the defiant message, but the 101st held out until reinforcements arrived on Dec. 26, 1944.

The battle began Dec. 16, but both the museum's tour and a tour organized by Veterans of the Battle of the Bulge, with 10 veterans, 38 family members and two other tourists, elected to start before the actual anniversary and get home before Christmas. The veterans' trip runs Dec. 8-18 and the museum's Dec. 11-20.

The group is accompanied by a curator from the museum in New Orleans, Larry Decuers, as well as a historian who has written about the six-week battle, Alex Kershaw, author of "The Longest Winter."

The tour participants, who paid $5,000 each for the trip, are among thousands of people who take trips each year affiliated with museums, alumni groups and other nonprofit organizations.

The groups use travel to cultivate donors, according to J. Mara DelliPriscoli, founder of Travel Learning Connections Inc., which organizes an annual conference about such trips. "They know that donors give and give more often when they travel," said DelliPriscoli.

Museum trips let curators and other officials get close to donors, said Paul Johnson, who works with art museums for the fundraising consulting firm Alexander Haas of Atlanta. "You're with them 24/7, with shared experiences and a lot of shared meals," he said.

That's "like gold," said Jim Sano, who ran an educational travel agency before becoming the World Wildlife Fund's vice president for travel, tourism and conservation. "When one looks at major gifts, one of the maxims is `People give to people' - not `people give to annual reports or direct mail solicitations,'" he said.

Some big museums, like the World War II Museum, the Metropolitan Museum of Art and the Smithsonian Institution, have staffs to create and market the tours, but most use specialized tour operators, DelliPriscoli said.

The World War II museum has been leading such trips for years and plans several World War II-themed trips to Europe each year.

The Battle of the Bulge began in Belgium's Ardennes forest, where the U.S. Army was training newly arrived infantry divisions. Snow and fog hampered the Allied effort, and unknown to U.S. intelligence, Germany was forming up 30 divisions for a major offensive campaign to divide the Allied army and recapture the port of Antwerp. The German attack created a bulge 60 miles deep in the Allied line. The Allies didn't regain the line until Jan. 28, 1945. It was one of the largest and bloodiest battles of World War II.

Museum affiliation allows perks that most tours can't offer, such as visits to collectors' homes and private, behind-the-scenes tours at museums abroad, Johnson noted.

For example, a former director of the 101st Airborne museum Le Mess in Bastogne, Belgium, is leading a battlefield walk for the World War II Museum group, said Peter Boese, the World War II museum's associate vice president of program development and sales.

He said the tour also includes a trip to La Gleize, Belgium, location of the statue of the Madonna that became a centerpiece of the book "Monuments Men" and its movie adaptation.

"It's a tiny little church. Most people don't know it's there. We get the keys from the priest," he said.