Powell was on a business trip in Hong Kong, watching results on television. Suddenly, it hit him.
"I'll never forget the words that came to me. And the words that I whispered to an empty room: My God, we did it. We did it," Powell said at a breakfast honoring Dr. Martin Luther King Jr., the day before Obama becomes the nation's first black president.
Powell made history also, as the nation's first black secretary of state, serving from 2001 to 2005. He is now a strategic limited partner for a venture capital firm.
Of Obama's election, he added: "What a tribute to our country, what a tribute to our system, what a tribute to the memory of the man we are honoring today - a man who said he wanted his children to be judged not by the color of their skin, but by the content of their character."
Powell said if King were alive, he would be at Tuesday's inauguration, beaming with pride as Obama takes the oath of office.
"I am just as sure that after congratulating President Obama, Martin would tug on him and say 'O.K. Mr. President, I need to see you tomorrow about a few things,'" Powell joked.
"He would never rest, he would never be satisfied, he would still be beating that drum," Powell added. "But he is not here. So it is up to us ... we must all come together to support our new president in who we have placed such hope and such expectation."