It will be a moment, a moment when the entire world watches, as the United States of America inaugurates our first African-American president.

There will be parties. There will be cheering. There will be speeches. I suspect a lot of people will probably start to cry.

Busloads of people, thousands of them, are making the trek to Washington, D.C., to witness the historic event, and millions more will be glued to their sets at home.

The donors, big and small, will feel proud. The media will chatter about what a big day it is, and all the volunteers who made the phone calls and sent the e-mails and registered the voters and went door to door will be elated because, thanks to their hard work, an idea that once seemed improbable has become real.

But there are some other people who also contributed to this moment. We’re not going to see them at any of the inaugural balls or marching in the parade. They don’t have front-row seats at the swearing-in ceremony and they won’t be interviewed on television.

But I suspect that they’ll be there during that moment when the Obamas walk up the steps to enter the White House.

A strong, silent group of contributors who I hope realize that, without them, this moment never could have happened.

They didn’t vote for him, they didn’t raise money and they certainly didn’t make YouTube videos.

But they’ll be by the first family’s side nonetheless, because they’re the unsung heroes whose literal blood, sweat and tears built the house that the Obamas will now call home.

In a grand full circle moment, America’s first black president will walk up steps that were built by slaves.

I’ve often imagined what it would be like to go back in time and tell those slaves how things worked out.

Imagine standing there at the foot of the White House steps, watching as the crew of black men hauled the stones in place, sweat streaming down their bodies, eyes downcast and their hands gnarled and mangled from years of hard labor.

Imagine walking up to the oldest, most tired-looking one, knelt down near the bottom of the steps as he struggles to push another rock in place. Imagine bending over and whispering in his ear:

“One day, on this very spot, a black man will stand with his wife and two beautiful daughters. He won’t be wearing laborers’ rags; he’ll be wearing a suit.

“As he stands with his family at the foot of these stairs, the eyes of the world will be upon them, but they’ll be thinking about you.

“They’ll pause right here on this very spot and, as they look up at the doors of the house they are about to enter, they will send you, and every other worker on this site, a silent prayer of gratitude and thanks.

“Because they want you to know that you mattered, that your life was not for nothing. Because these rocks that you’re laying, they are the very surface the black man and his family will walk on before they ascend the stairs, so that he can begin his work as President of the United States.”

The old slave would have thought that you were crazy if you had spun him that tale. But perhaps somewhere, somehow, he now knows.

I pray that they all do.