Democratic presidential hopeful Barack Obama, in Philadelphia, Tuesday delivered a speech on race relations in the United States. Here is the transcript: We the people, in order to form a more perfect union. Two hundred and twenty one years ago, in a hall that still stands across the street, a group of men gathered and, with these simple words, launched America's improbable experiment in democracy. Farmers and scholars; statesmen and patriots who had traveled across an ocean to escape tyranny and persecution finally made real their declaration of independence at a Philadelphia convention that lasted through the spring of 1787....