Barack Obama (L) and his wife Michelle Obama are present at the presidential inauguration ceremony held in front of the U.S. Capitol in Washington D.C. Jan. 20, 2009. [Zhang Yan/Xinhua]

"We will build the roads and bridges, the electric grids and digital lines that feed our commerce and bind us together. We will restore science to its rightful place, and wield technology's wonders to raise health care's quality and lower its cost. We will harness the sun and the winds and the soil to fuel our cars and run our factories. And we will transform our schools and colleges and universities to meet the demands of a new age, " he said.

Obama also called for "greater cooperation and understanding between nations" and pledged to "begin to responsibly leave Iraq to its people, and forge a hard-earned peace in Afghanistan."

He illustrated a new set of foreign policies. The new president said, "To the Muslim world, we seek a new way forward, based on mutual interest and mutual respect;" and "to the people of poor nations, we pledge to work alongside you to make your farms flourish and let clean waters flow."

To America's enemies, Obama took a tough stand. "We will not apologize for our way of life, nor will we waver in its defense, and for those who seek to advance their aims by inducing terror and slaughtering innocents, we say to you now that our spirit is stronger and cannot be broken; you cannot outlast us, and we will defeat you," he said.

In the address, Obama also paid tribute to his predecessors, including former President George W. Bush.

"I stand here today humbled by the task before us, grateful for the trust you have bestowed, mindful of the sacrifices borne by our ancestors. I thank President Bush for his service to our nation, as well as the generosity and cooperation he has shown throughout this transition," he said.

An estimated 2 million people, braving the cold weather, gathered in Washington to witness the historic inaugural ceremony, surely breaking the historic record of 1.2 million people attending the inauguration of Lyndon Johnson in 1965.

After the inauguration, new President Obama and First Lady Michelle Obama escorted their predecessors, George W. Bush and his wife Laura, to a helicopter exchanged handshakes before they boarded the helicopter which will take the Bushes home in Texas as a private citizen.

The Bushes will first stop at Andrews Air Force Base before flying to Midland, Texas, where Bush spent his early days as a child.