elect Barack Obama and his wife Michelle took their first postelection White House tour Monday, officially setting in motion America's intricate minuet of transition from one president to the next. President George W. Bush and first lady Laura Bush greeted the Obamas, who arrived 11 minutes early on a sunny fall day with moderate temperatures and colorful – but fading – autumn leaves. The Obamas stepped out of a black limousine, were welcomed by the Bushes and escorted into the Executive Mansion that they'll call home in a little more than two months. Television pictures then showed Bush and Obama talking as they walked alone under the White House Colonnade, pausing for pictures before entering the Oval Office. It was Obama's first time in the presidential chamber. Bush allowed Obama to enter the historic office first as the 43rd and 44th US presidents prepared for a private talk about the challenges of leading a nation freighted in this hand-over of power by a severe economic downturn and two wars. The country's troubles fall to Obama when he takes office Jan. 20. Bush, who had endorsed Republican John McCain, lauded Obama's victory as a “triumph of the American story,” as he issued a warm invitation for the next president and his wife, Michelle, to their future home. Obama will be the country's first black president and takes office with fellow Democrats firmly in control of the White House and both houses of Congress. Before the meeting began, White House press secretary Dana Perino said she could not offer a detailed preview. “It's just very private,” she told reporters at the daily White House news briefing. “And I'm sure that this won't be the only time that they speak.” After arriving, the Obamas were taken to the Diplomatic Reception Room where they were to meet the chief usher of the White House, Perino said. Bush and Obama were not scheduled to make any public statements during their time together. Mrs. Bush was giving Mrs. Obama a tour of the first family's living quarters, including the bedrooms used by children of past presidents. Perino said the two women were expected to talk about living in one of the world's most famous building, from family life to the help provided by executive staff. The Obamas have two daughters: Malia, 10, and Sasha, 7. Obama started his day in Chicago, dropping the two girls at school, each with a kiss, and then going to a gym for a workout. When asked last week about his meeting with Bush, Obama answered: “I'm going to go in there with a spirit of bipartisanship, and a sense that both the president and various leaders of Congress all recognize the severity of the situation right now and want to get stuff done.” Josh Bolten, Bush's chief of staff, said Bush and Obama will be the only ones in the room when they meet. Unlike the incoming president, Bush knew his way around the Oval Office by the time he was elected in 2000 – his father had been president. Still, like many before them, President Bill Clinton and President-elect Bush had their own private meeting.