WASHINGTON - Barack Obama and his family would make history Tuesday as the first black first family to move into the White House, a mansion largely built by slaves, who also helped shape the national capital.

And until the Civil War, when Obama’s idol Abraham Lincoln freed slaves, 12 American presidents owned slaves and eight of them, starting with George Washington, owned slaves while in office. Almost from the very start, slaves were a common sight in the executive mansion.

The US Capitol, the home of nation’s parliament, on whose steps Obama will be sworn-in as the leader of the world’s oldest democracy, too was built by a workforce that was made up largely of slaves from houses and farms in Virginia, Maryland and the capital.

It was a slave named Philip Reid who figured out how to bronze the Made in Rome plaster cast of the 19-foot-6-inch (5.85 metre) Statue of Freedom in pieces and then put it together so it could be hoisted on top of the Capitol dome.

The Mall, the large expanse of land running through downtown Washington, linking the Capitol to the Lincoln Memorial, where a million plus people are expected to throng to witness history in making, held markets where slaves were bought and sold before the Civil War.

On the spot where the National Archives, which holds the Lincoln’s original Emancipation Proclamation of 1863 freeing the slaves, stands today was a well-known slave market called Lloyd’s Tavern.

Now, the Obamas are moving into the White House.

Obama himself is the son of a Kenyan father and a white American mother, but his wife Michelle learned this year that one of her great-great grandfathers was a slave who worked on a rice plantation in South Carolina.

‘The apple cart has been turned over here when you have the Obamas - the first African-American couple - now actually management and you are having in some cases white Americans serving them,’ according to presidential historian Doug Brinkley.

Though Michelle Obama’s ancestors had to come through the ordeal of slavery, ‘Her children are sleeping in the room of presidents,’ Brinkley said.’It’s a very great and hopeful sign.’

A list of construction workers building the White House in 1795 includes five slaves - named Tom, Peter, Ben, Harry and Daniel-all put to work as carpenters. Other slaves worked as masons in the government quarries, cutting the stone for early government buildings, including the White House and US Capitol.

According to records kept by the White House Historical Association, slaves often worked seven days a week-even in the hot and humid Washington summers.

In 1800, John Adams was the first president to live in the White House, moving in before it was finished. Adams was a staunch opponent of slavery, and kept no slaves. Future presidents, however, didn’t follow his lead.

Thomas Jefferson, who succeeded Adams, wrote that slavery was an ‘assemblage of horrors’ and yet he brought his slaves with him. Early presidents were expected to pay their household expenses themselves, and many who came from the so-called ’slave states’ simply brought their slaves with them.

Martin Van Buren, William Henry Harrison, Andrew Johnson and Ulysses S. Grant all owned slaves but not during their time in office. James Madison, Jefferson’s successor, held slaves all of his life including while he was in office.

James Monroe, Andrew Jackson, John Tyler, James K. Polk and Zachary Taylor all owned slaves while they were in office. The last of these, president Taylor, said owning slaves was a Constitutional right and he said slave-owners like himself would ‘appeal to the sword if necessary’ to keep them.