Barack Obama warned on Saturday that America faces "a time of great challenge" as he launched pre-inauguration festivities with a special train trip to Washington, where in three days he will become president of the United States, according to Reuters. Obama, a Democrat who will take office on Tuesday during the sharpest economic downturn in generations, has vowed to hit the ground running with plans to spend hundreds of billions of dollars to jolt the country out of a deepening recession. But he also has stressed it will take time and sacrifice to turn the economy around, casting a somber shadow over the celebrations marking his victory. "Together, we know that this is a time of great challenge for the American people. Difficult days are upon us, and even more difficult days lie ahead," Obama said in a weekly radio address released on Saturday. "Our nation is at war. Our economy is in great turmoil. And there is so much work that must be done to restore peace and advance prosperity." Outgoing President George W. Bush, a Republican who leaves the White House with some of the lowest popularity ratings on record, has used a series of farewell speeches to defend his eight years in office, including his response to the Sept. 11 attacks in 2001 and his decision to launch the war in Iraq. "I have followed my conscience and done what I thought was right," Bush said in his final radio address on Saturday. "You may not agree with some tough decisions I have made. But I hope you can agree that I was willing to make the tough decisions." Obama and his family boarded a special train in Philadelphia, one of the cradles of U.S. democracy. The slow trip will take them through Delaware, where they will pick up Vice President-elect Joe Biden, and then onto Baltimore before Saturday evening's arrival in the capital. "We are here to mark the beginning of our journey to Washington," Obama told a cheering crowd at the train station in Philadelphia. "It was here in this city that our American journey began." The 137-mile (220 km) train journey -- which will be marked by several stops for speeches and "slow rolls" so people can wave at the Obamas -- is the official start of a weekend of parties, concerts and shows to celebrate the inauguration. Obama got a big boost this week when Democrats in the House of Representatives unveiled an $825 billion economic stimulus bill that largely adheres to the measures the president-elect has requested. Also on Thursday, the Senate voted to give Obama authority to spend the $350 billion remaining from a $700 billion financial industry bailout fund created in October. His incoming White House chief of staff, Rahm Emanuel, told a conference of mayors in Washington the new administration was focused on making the U.S. economy stronger and more competitive. "We have got to invest in things that work in a different way," Emanuel said. The priorities, he said, included investing in energy independence, modernizing healthcare and expanding coverage, delivering universal broadband Internet for a digitized economy and upgrading schools -- all of which will add to the already staggering price tag facing the Obama administration.
