JACKSONVILLE, Fla. (AP) _ A green flag sent about 100 Europeans thundering down the road in their vintage Mustangs Friday for a seven-week tour of the United States to celebrate the 25th birthday of the classic Ford sportscar.

Some 37 pre-1973 Mustangs were shipped into the Port of Jacksonville for the 7,000-mile trek. Drivers from Switzerland, England and the Netherlands were joined on the first leg of the journey to Pensacola by about 50 Mustangs from the Southeast.

John Manners, a Swiss maintenance electrician who organized the so-called American Pony Drive, said driving a Ford Mustang across the United State is akin to an American driving a Porsche across Germany.

''It provides an excellent excuse for everybody to do what they've always wanted to do,'' said Manners, who has been planning the tour for three years.

The cars will cover 200 miles a day or less, Manners said. A large number of American Mustang enthusiasts are expected to join in along the way.

Jerg Pflugger of Solothurn, Switzerland, proudly displayed his restored 1972 Mustang, which is painted with a design or red, yellow and orange. ''I wanted some exciting painting,'' he said.

Jeff and Jane Holm, Mustang owners from Roswell, Ga., joined the tour and planned to travel to New Orleans before returning home.

Holm, 47, recently restored the car he bought new in 1964, putting in a new engine and undercarriage. ''We were just kids when we bought this car,'' he said. ''It was our fun car.''

From Pensacola, the Mustang caravan will make stops in New Orleans, Dallas, Tulsa, Okla., Albuquerque, N.M., and Flagstaff, Ariz., among other stops.

The caravan will hit Las Vegas on April 11, where 1,000 members of Mustang clubs across the United States are expected make the run to Los Angeles.

The Mustangs leave Los Angeles on April 21 for stops in, to name a few cities, Little Rock, Ark.; Memphis and Nashville, Tenn.; Columbus, Ohio; Indianapolis and Pittsburgh, before ending in Baltimore, on May 8.