From PEOPLE Magazine Click to enlarge
They skipped the customary "something borrowed, something blue," but on the morning of his wedding day, the groom did put on something old: a frayed T-shirt he had worn nearly 17 years earlier when he first met his future bride. Chelsea Clinton was just 13 then, Marc Mezvinsky 16, both brought along to the annual political Renaissance Weekend their parents attended in South Carolina. The shirt was long forgotten, but turned up sometime after he and Clinton started dating in 2005. After that Mezvinsky made sure to hold on to it, he told nearly 500 wedding guests gathered at the Astor Courts estate in Rhinebeck, N.Y. It was one of many romantic moments indicating how meant-to-be this union was. The couple, who were close friends at Stanford University, "are not people who usually stand around grinning," says one guest. "But the whole weekend they radiated joy. No one doubted the strength of their feelings for each other."

As a testament to those feelings, both families made sure that July 31, and the days surrounding it, were all about Marc and Chelsea and not, as they could have been, about networking. "The people coming are her friends and people who have been meaningful in her life," mother of the bride, Secretary of State Hillary Clinton, 62, said days before. No Obamas were present, nor herds of Hollywood A-listers. Oprah? Nah. "This was Marc and Chelsea's list," says wedding planner Bryan Rafanelli. Guest Ted Danson, whose wife Mary Steenburgen is an old Clinton pal from Arkansas, joked accurately: "Are we the only celebrities here?"

Before the big day, President Bill Clinton, 63, made his daughter two promises: that he would take better care of himself by losing some weight and that he would try not to cry. With a vegetarian diet and a lot of walks, he kept the first promise. The second was harder. "He was pretty calm before," says a guest. "But walking down the aisle, he was stoic, trying to contain his emotion." He held it together, but others teared up as the two officiants, a Rabbi and a Methodist minister, told him, " 'It's time to say goodbye,' " recalls Bill's cousin Marie Clinton Bruno. "He gave her a kiss, and she walked up the stairs."

Chelsea, 30, continued on her own, radiant in a strapless silk organza gown designed by Vera Wang. "She looked stunning," says one witness. "It was like time stopped." With its long train, full veil, and crystals on the belt (a detail requested by Chelsea), the dress was an apt metaphor for the whole affair, says Rafanelli. "It was timeless and classic, with a little bit of sparkle."

"The wedding didn't feel lavish or over-the-top," says a guest. (Nor did it, as was reported, cost $3 to $5 million; in fact it was within six figures, says a source familiar with the budget.) Despite a procession of 12 bridesmaids in lavender Vera Wang gowns and 12 groomsmen decked out in Burberry ties, says this guest, "somehow it seemed intimate."

Intimate and secret-until now. "Thank you, Thank you," wrote the couple in their program. "We are profoundly grateful to be surrounded by our family and friends as we begin our new life together." The interfaith ceremony (the bride is Methodist and the groom's family are conservative Jews) took place on a grass field, under a chuppah, a canopy, with "a lot of organic flowers: limelight hydrangeas, white roses, green parrot tulips," says Jeff Leatham, the florist. The hour-long nuptials included the seven traditional Jewish blessings, vows that the bride and groom wrote themselves and a reading of a love poem, "The Life that I Have," by Leo Marks. ("The life that I have/Is all that I have/And the life that I have/Is yours.") There were memorable moments: Bill lifted Chelsea's veil to whisper a few last words before giving her away; Chelsea accidentally dropped Marc's ring. When Marc, 32, broke the glass under his shoe at the ceremony's end, the crowd, which included all of his 10 siblings, erupted in applause as the couple enjoyed their first married kiss. "It wasn't a smack and wasn't full-blown," says a guest. "She held his face as if she would cherish him forever."

After a quick gown change (into an ivory tulle Vera Wang dress with a "sexy back" says an observer), the newlyweds then made a splash with their sultry first dance. To "Feeling Good"-and with choreography by Dancing with the Stars pro Maksim Chmerkovskiy-Chelsea at one point took off Marc's jacket, and he lifted her up. "It was an amazing, funny, unexpected, sexy dance," says a friend of the bride's. "Bill and Hillary seemed to love it." The next dance was for the father of the bride: Chelsea and Bill swayed to "The Way You Look Tonight." As the song came to a close, she wrapped her arms around her dad and he swung her in a circle. As for the groom's family, his mother, former Pennsylvania Rep. Marjorie Margolies, noted earlier that while in Congress, she supported Clinton's budget, despite it being an unpopular choice, and joked, "I told Bill I would vote for his package, but he'd have to give me his firstborn."

For dinner the guests chose between arctic char, braised short ribs and a vegetarian dish. The four courses were broken up by spins on the dance floor-yes, that was former Secretary of State Madeleine Albright "boogying," reports one guest. The Clintons delivered heartfelt words to their daughter. "Both made it clear that while they've led interesting lives, the most important thing they've done is raising Chelsea," who is pursuing a PhD at NYU, says a friend. The couple live in an apartment in downtown New York, along with their dog, a Yorkshire terrier named Soren. Bill, who kept referring to Marc, a hedge fund trader, as his son, said how proud he was to welcome him into his family-and how relieved he was no longer to be the "outnumbered" male in the household. "Now," the former President said, "the playing field is even. I have someone else on my side." Later the guests hoisted all four parents-including Marc's dad, former Iowa Rep. Ed Mezvinsky-in chairs, a Jewish custom.

The party didn't end there. At midnight guests were ushered into a nightclub tent with two bars and snacks of sliders and tacos, for more dancing. After 4 a.m. Marc scooped his bride in his arms and carried her off into the night. The details of the honeymoon were such a closely guarded secret that even the bride had no idea where they were going. Says a family friend: "He just told her what to pack."