For nearly three years, the stainless steel legs of the Gateway Arch rose ever higher along the Mississippi riverfront.

Finally, workers put the last section into place on Oct. 28, 1965, forever silencing jokesters who had predicted the legs of the giant "croquet wicket" would never meet.Twenty-five years and 64 million visitors later, the arch is considered by many to be St. Louis' crowning glory. It has become the nationally recognized symbol of the city, and civic leaders say it was the catalyst for a rejuvenation of a decaying downtown.

"It's been probably the greatest single thing that has ever happened to St. Louis," said Arthur Wright, a public relations man who was one of the arch's earliest civic supporters.

The 630-foot structure is the country's tallest national monument. It is the centerpiece of the National Park Service's Jefferson National Expansion Memorial, built to honor Thomas Jefferson and his 1803 Louisiana Purchase, as well as the city's role as the gateway to the West.

The memorial cost $30 million, with the arch accounting for $12 million. The federal government paid three-fourths and the city the rest.

Since its opening in 1967, millions of people have ridden to the observation room at the top in tram cars that travel slowly up the inside of each leg, tilting to stay level.

"Amazed; in awe," said Ed Green, a recent visitor from Buford, Ga. "I pictured it just to be a concrete monument. I had no idea you could go up inside of it. The view was excellent, very peaceful."

The rangers who work at the arch have heard it all, but Lisa Schober said she never tires of seeing people's reactions.

"It's always the same things," Schober said. "From kids, it's `awesome.' From older people, it's `I made it, I'm here.' "

The arch's architect, the late Eero Saarinen, came up with the design while experimenting with pipe cleaners on his living room floor. Its shape, in technical terms, is a catenary curve.

It is designed to sway 9 inches one way or the other in 150 mph winds. On windy days, when there are gusts up to 35 or 40 mph, people in the top of the arch can feel it move several inches.

But "to most people, an inch feels like a foot," Schober said. "Everybody thinks it's moving even when it's not."

"The arch is as closely identified with St. Louis as the Eiffel Tower is with Paris," said Ed Ruesing, president of Downtown St. Louis Inc., the city's chamber of commerce.

Business leaders say the arch revitalized downtown St. Louis, which like other cities had experienced suburban flight during the 1950s and 1960s.

During the last three decades, 50 office buildings have been built downtown and more than 75 have been renovated - an investment of more than $3 billion.

"I don't think it's an exaggeration to say that the entire redevelopment of downtown St. Louis has progressed from the construction of the arch," Ruesing said. "Real estate investors ever since have scrambled to build as close to the arch as possible."

The arch has drawn visitors from around the world, but as with many monuments, some folks living in its shadow never get around to seeing it.

Clarence Liebman, 66, has lived in St. Louis most of his life but until this month had never visited the arch.

"Remember, the lines were long the first 25 years," he said.