On Tuesday, hundreds of thousands of people braved freezing temperatures to witness firsthand the inauguration of Barack Obama, the 44th president of the United States and the first African American to hold the position. Standing before a crowd that stretched across the National Mall toward where Martin Luther King Jr. made his historic speech about racial equality in 1963, Obama addressed the nation for the first time as its president. In his speech, he spoke of a "new era of responsibility" and reassured Americans that the challenges the country now faces will be met.