Obamas host British Prime Minster David Cameron at state dinner President Obama and his wife, Michelle, hosted the sixth state dinner of their tenure Wednesday evening, honoring British Prime Minister David Cameron in a celebration of spring in a tent on the White House's South Lawn. The black-tie gala drew Hollywood celebrities, deep-pocketed donors, titans of government and the reigning king of golf: Northern Ireland's Rory McIlroy. Other notables: investment guru Warren Buffett, actor George Clooney, journalist Charlie Rose, Vogue magazine editor Anna Wintour and British actor Damian Lewis, who stars in TV's "Homeland," which counts the president as a fan. Guests from Chicago included White House advisor Valerie Jarrett and Obama campaign backers Neil Bluhm, Fred Eychaner and Rajiv Kumar Fernando. Chicago magnate Jim Crown and his wife, Paula Hannaway Crown, also attended. "We're honored to be here," Jim Crown said. California was represented at the dinner by Hollywood, the technology industry and gay rights activists. Clooney was joined by British-born actor Idris Elba, now a resident of Beverly Hills; actor Barry Karas; and producer James Lassiter. Chad Griffin, the newly appointed head of the Human Rights Campaign, was there, along with Dana Matthew Perlman, who serves on the campaign's board and is an Obama fundraiser. Briton Jony Ive, who designed the iPod and other iconic Apple products, was invited, as was John W. Thompson, a former chief executive of Symantec, who now heads Virtual Instruments, a software firm. The Obamas showcased the capital's early burst of spring at the state dinner, hosting the soiree in a glass-sided tent. Tall citron-colored candles and lush bouquets of purple and green hydrangeas decorated tables draped in stripes or bold geometric prints. The four-course menu's main offering was Bison Wellington, billed as a "marriage" of the two countries" traditions. The first course was crisped halibut, the second a salad with greens from the White House garden. Dessert was an old British favorite, warm lemon pudding. The menu was an ode to America's West: the halibut was from Alaska, the bison was from North Dakota, and huckleberry that flavored the dessert was from Idaho. Wines from the U.S. were paired with each course, but the White House did not divulge their names. After the meal, the reception was to feature performances by R&B singer John Legend and Mumford and Sons, a British folk band said to be a favorite of Cameron's wife, Samantha, known as "Sam Cam." Michelle Obama wore a teal off-the-shoulder gown by Marchesa, complementing Samantha Cameron's lace-fringed, blue print dress. Before the big bash, MIchelle Obama invited U.S. and British schoolgirls to feast their eyes on the bold-colored tables and sample the pudding. She told the girls they'd be the first to taste it, then remembered: "I think me and Grandma and a couple of people, we've tasted the desserts." Other British prime ministers feted at White House state dinners were Tony Blair in 1998, Margaret Thatcher in 1981 and 1988 and James Callaghan in 1977. Queen Elizabeth II was honored at a white-tie affair by President George W. Bush in 2007.