Every four years sounds of construction take over the front of the White House. But this time around, there's something poignant about them.
CBS News chief White House correspondent Jim Axelrod said to White House Historian William Bushong: "We're surrounded by workmen here and they're getting the Obama review stand ready. Fair to say there would have been slaves right here a couple hundred years ago?"
Bushong replied: "Certainly."
It may not be new to Bushong, but many of the rest of us may be surprised that slaves built much of the White House.
Washington, D.C., in fact, is "right smack in the middle of, between two states that were slave-holding states, Maryland and Virginia," Bushong points out.
More than 200 years ago, near the White House, there were brick kilns, wood-working sheds and tents for sleeping. It was a slave village.
The distance between living out there and living inside the White House is not something that cannot measured in yards.
Three weeks ago, the National Archives' Reginald Washington saw a batch of 200-year-old wage records for slaves for the first time.
"They're paying to Mr. James Claggett for the hire of a negro, George," Washington said.
This sheds light on an especially symbolic chapter of what's been called our nation's original sin.
Talking further to Washington, one learns more about James Hoban, the architect of the White House, who had three slaves working.
"And usually they're gonna list the negroes only by their given name, not their surname," Washington said.
But not much about Ben, Harry and Daniel themselves comes across. Just their 23 days worked and money earned is documented - but that money went to their master, of course.
"The slave owners were paid for the services of their slaves just as they were paid for the services of their horses or wagon," Washington said.
In his 30 years handling documents at the White House archives, nothing has hit him as profoundly as this.
"They never could imagine in their wildest dreams that a man of color, or an African-American would one day sit in the White House itself where they toiled to build this," Washington said.
Less than six weeks from now those wildest dreams come true.