Sen. Barack Obama (D-Ill.) accepted the mantle of victory late Tuesday evening, casting his election to the presidency in historic terms and vowing with soaring rhetoric to bring the change and unity he has promised to the country.

Appearing before ecstatic supporters in Chicago, Obama alluded frequently to his becoming the first African American to be elected president and the change it represents.

“If there is anyone out there who still doubts that America is a place where all things are possible, who still wonders if the dream of our founders is alive in our time, who still questions the power of our democracy, tonight is your answer,” Obama said.

Americans, he said, had sent “a message to the world that we have never been just a collection of individuals or a collection of red states and blue states — we are and always will be the United States of America,” he said. Americans have “put their hand on the arc of history and bent it once more to the hope of a better day,” he said. “It’s been a long time coming, but tonight, because of what we did on this day, in this election, at this defining moment, change has come to America.”

Toward the end of his remarks, he iterated the historic events in the life of a 106-year old black woman that culminated in her voting for Obama today.

Obama tipped his hat to his defeated opponent, Sen. John McCain (R-Ariz.). “He has endured sacrifices for America that most of us cannot begin to imagine,” Obama said. “We are better off for the service rendered by this brave and selfless leader.”

Obama also thanked his running mate, Sen. Joseph Biden, (D-Del.), and lauded his staff who had created “the best campaign in the history of the United States of America.”

Obama acknowledged the difficult task ahead, noting that the United States is fighting two wars and facing an economic crisis. “The road ahead will be long,” he said, “but we as a people will get there.”

Obama also said he wants the support of those whose backing he said he had not yet earned. “I hear your voice, I need your help, and I will be your president too,” he said.

President Bush called Obama Tuesday night to congratulate him and invite him to visit the White House when he is ready. Obama is expected to begin moving on his transition as early as today.