Climate change is one of the issues I worry most about because its impacts are enormous. But they're gradual, they're not immediate.

Since I'm the president and Democrats have controlled the House and the Senate, it's understandable that people are saying, you know, 'What have you done?'

Congress is hard to deal with, dealing with, you know, multiple parliaments and commissions and unions and this and that and the other, that's very complicated.

Throughout history, Islam has demonstrated through words and deeds the possibilities of religious tolerance and racial equality.

Because as tough as things have been, I am convinced you are tougher. I've seen your passion and I've seen your service... I've seen a generation eager, impatient even, to step into the rushing waters of history and change its course.

Iran was nearing completion of a new reactor capable of producing plutonium for a bomb.

Beside the two wars he inherited in Iraq and Afghanistan, and promised to end, a financial crisis at home had pushed the United States to the brink of another Great Depression. When we spoke with the new president in March of 2009, the economy was losing 800,000 jobs a month, the government was throwing hundreds of billions of dollars at failing banks, and the auto industry was on the verge of collapse. Politically pummeled from all sides, Obama did his best to keep a sense of humor.