The sun shone on a generation yesterday, as the largest gathering of World War II veterans since 1945 assembled on the Mall to see their long-awaited memorial assume its place in the center of Washington's defining landmarks.

About 117,000 people with tickets, and tens of thousands of others, witnessed the dedication of the National World War II Memorial, a 7.4-acre tribute in granite and bronze that has been 17 years in the making.

"It is a fitting tribute, open and expansive like America itself, grand and enduring like the achievements we honor," President Bush told the crowd. "When it mattered most, an entire generation of Americans showed the finest qualities of our nation and of humanity. . . . We will raise the American flag over a monument that will stand as long as America itself."

The two primary concerns of the ceremony's organizers -- security breaches and serious medical problems among the mostly elderly crowd -- never materialized. Gentle breezes and temperatures in the low 70s helped ease the day's strain on the veterans and their spouses, who spent hours in open-air viewing areas. Emergency medical tents were lightly used, with doctors and nurses occasionally washing a cut from a fall or bandaging a turned ankle.

More than 1,000 police personnel from at least 35 law enforcement agencies were on duty, but they reported no serious incidents.

"It's been about perfect," said Henry Royce, 85, an Army veteran from Stowe, Vt. "Everybody's been so good to us. It seems like they really care."

The event had its share of sadness, including a moment of silence for the more than 400,000 U.S. service members killed in the war. But the day proved more celebratory than somber. As the crowd waited for the dedication program to begin, big bands played standards from the 1940s, and impromptu dancing could be spotted within the rows of men and women in their seventies and eighties.

Guy Kemp, 85, a former Navy Seabee who served in the Pacific, found himself jitterbugging to "Chattanooga Choo-Choo" with a woman he didn't know.

"This really gets me way down deep, talking to all these people and seeing all of this," said Kemp, who confessed that his son had to talk him into making the trip from his home in Winter Haven, Fla. "It's the best thing I've done in my life."

The ceremony and the memorial were conceived as a comprehensive tribute to a rapidly dwindling group. World War II veterans are dying at a rate of about 1,100 a day, according to the Department of Veterans Affairs. The generation from that conflict -- the youngest of whom are now in their mid- to late seventies -- has witnessed a renaissance of appreciation for their wartime achievements.

Two figures who helped spark that renaissance -- Tom Brokaw, the newscaster and author of books chronicling "The Greatest Generation," and actor Tom Hanks, star of "Saving Private Ryan" -- were among those who took the stage during the 90-minute ceremony. Other speakers included former senator Robert J. Dole, who led the $175 million memorial's private fundraising drive, and Rep. Marcy Kaptur (D-Ohio), who first proposed the memorial in Congress in 1987 after an Ohio veteran, Roger Durbin, raised the issue with her a year earlier. Former presidents Bill Clinton and George H.W. Bush were in the audience.

Although offspring of familiar names from the war era -- Roosevelt, Churchill, Eisenhower -- could be found in the crowd, the focus of the attention throughout the day remained squarely on the veterans, who had served with little fanfare. They were also the ones who responded to plans for the dedication with an enthusiasm that caught organizers by surprise.

Before it began distributing tickets to the event this year, the American Battle Monuments Commission had estimated that one-third of those occupying the 117,000 ticketed seats would be members of the World War II generation and the rest would be younger people. Instead, World War II veterans and their spouses accounted for about 60 percent of those in the ticketed seats yesterday, according to commission spokeswoman Betsy Glick.

"I didn't figure I'd ever see this big of a crowd at one time again, so that's why I wanted to be here," said Hilton Olde, 83, a Navy veteran from Wapello, Iowa, who was at Pearl Harbor on Dec. 7, 1941. "It's quite spectacular."

The American Legion's national headquarters surveyed its local posts and estimated that 160,000 World War II veterans planned to be in Washington for this weekend's festivities. But some might have stayed away from yesterday's crowded and tightly secured ceremony, said Joe March, a spokesman for the American Legion.

"We think that's a pretty close estimate," March said. "I know of no other event that's had so many World War II veterans come together in one place like this."

In addition to the ticketed guests, tens of thousands watched the proceedings from other parts of the Mall. Few spectators had a direct view of the stage, which was set up on 17th Street between Constitution and Independence avenues, just east of the memorial. Most saw simulcasts of the ceremony on large video screens.

Although the seating areas didn't open until 8 a.m., veterans were lining up at the security gates as early as 6:20 a.m., Glick said. Crowds continued to arrive steadily until about a half-hour before the 2 p.m. ceremony; some waited as much as a half-hour to pass through security checkpoints and metal detectors.

But in contrast to the staggered arrivals, almost everyone wanted to leave at the same time after the ceremony ended. Bottlenecks followed, and long waits commenced. Thousands lined up for shuttles to return to charter buses at Robert F. Kennedy Memorial Stadium, resulting in waits of more than an hour. Several attendees -- many in wheelchairs -- said that their buses were not at their drop-off locations, which left them stranded and hoping to catch taxis or different shuttle buses to Metro stations.

"No buses have stopped here at all," said Linda Kus, who had been waiting for more than an hour after the ceremony with her father, Myles Bell, a World War II veteran from Mobile, Ala. "Everything has been fine until now."

Cathy Asato, a spokeswoman for Metro, said the long lines for its shuttle buses occurred because people left the ceremony at once and because there was more traffic congestion in the afternoon than in the morning.

Such headaches were minor compared with what organizers had envisioned as worst-case scenarios. Remembering that 500 members of the considerably smaller and younger crowd that gathered nine years ago for the Korean War Veterans Memorial's dedication were treated for heat exhaustion, planners staffed the Mall with scores of emergency medical personnel and physicians. Nine tents were equipped with cots, defibrillators and other medical supplies. But the weather gave them a break.

Alan Etter, spokesman for the D.C. Fire and Emergency Medical Services Department, said that by 6:30 p.m., 110 people were treated on the Mall and at Robert F. Kennedy Memorial Stadium, with 30 of them taken to hospitals. More than half the overall cases were related to heat exhaustion and the rest to slips and falls, he said. One of those treated -- a 93-year-old man who collapsed after complaining of trouble catching his breath -- seemed to fit Brokaw's characterization of a generation that returned "without whining or whimpering." Etter said that the man regained consciousness inside an ambulance, refused treatment, grabbed his cane and jumped out of the vehicle.

American Red Cross volunteer Marnie Dodson marveled at the World War II veterans who passed through her resting tent. "People are really in good shape," she said as she squeezed sunscreen into one veteran's hand. "They are a sturdy lot."

Earlier in the day, several hundred veterans, family members, congressional leaders and others gathered at Washington National Cathedral for an hour-long "Service of Celebration and Thanksgiving to God." The service, simulcast on screens on the Mall and at MCI Center, featured a tribute by former president Bush.

Bush asked for prayers not only for those who fought and died in World War II, but also for those serving in Iraq and Afghanistan.

"The scope of World War II may have been greater, but the anxiety and the pain is no greater," he said.

The dedication ceremony marked the peak of a weekend of war-themed events on the Mall. A "National World War II Reunion" exposition organized by the Smithsonian Institution and the American Battle Monuments Commission continues today from 11 a.m. to 7 p.m. The event includes exhibits of World War II equipment, tents where veterans can plan reunions, music and public discussions from notable veterans. For a complete list of today's activities, visit www.folklife.si.edu.

Tomorrow, the first Memorial Day parade in Washington in more than 60 years will start at 8 a.m. at Third Street and Madison Drive on the Mall and end three hours later at Independence Avenue and 12th Street SW. The parade, intended to honor World War II veterans, will be followed by a wreath-laying ceremony and memorial service at 11 a.m. at Arlington National Cemetery's Tomb of the Unknowns.

Staff writers Elaine Rivera, Jason Ukman, Bill Broadway, Manny Fernandez and Serge F. Kovaleski and staff researcher Bobbye Pratt contributed to this report.

Maj. Dwight Rickard of Fredericksburg, right, comforts his father, 84-year-old Alvin Rickard of Denver, during the memorial's dedication ceremony.Robert Wallace, 81, of Little Rock, who served in the Army during the Normandy invasion 60 years ago, explores the memorial after the dedication ceremony.Jim Smith, 77, of Tampa and other former soldiers salute during the national anthem. Except for a moment of silence for fallen U.S. soldiers, the day was celebratory.

Former presidents Bill Clinton and George H.W. Bush chat at the end of the ceremony. The veterans behind President Bush are Medal of Honor recipients. The dedication of the memorial went off with no security problems and few of the feared medical emergencies.