In a grand ceremony featuring President Obama, the First Lady, Laura Bush, and a stirring performance from Jason Moran, ground was broken yesterday on the newest addition to the National Mall and the nineteenth Smithsonian museum. The National Museum of African American History and Culture, with an expected completion date in 2015, will be a powerful monument to the contributions of black Americans to American history on a prime piece of real estate just between the Washington Monument and the American History Museum.

“This was true bipartisan effort, echoing the museum’s message of unity,” Wayne Clough, Smithsonian secretary, said of the $500 million building project (half funded by Congress). “What a magnificent location, in view of powerful symbolism. It is a fitting home for this museum, invoking the indelible threads that connect African American stories to the American tapestry.”

The soon-to-be-laid foundations would rest, the President remarked, where “lives were once traded, where hundreds of thousands once marched for jobs and for freedom. It was here that the pillars of democracy were built often by black hands.”

Their collections have swelled recently to somewhere around 20,000 objects, including a Jim Crow-era railroad car, trainer plane for the Tuskegee Airmen, and Harriet Tubman’s hymnal.

Its purpose, said museum director Lonnie Bunch in a White House YouTube clip, is “to create a safe space where people can talk and explore the history of African Americans in a way that’ll bring us to reconciliation and healing.” But he isn’t waiting around for the new building to start that conversation—exhibitions sponsored by the NMAAHC have already gone up in New York City and the first floor of the neighboring American History Museum, where last month they unveiled an exhibit entitled “Slavery at Jefferson’s Monticello: Paradox of Liberty.” As the title suggests, the exhibit raises the difficult questions of a nation founded in liberty that tolerated slavery, and more specifically, how the author and architect of many features of that nation owned 607.

When the museum tested the waters of public opinion about what it might focus on it became clear to Bunch that, “the most controversial, the most debated, the most feared, and yet the most needed subject to explore was the history of enslavement in America.”

“To some, slavery is best forgotten because the period of enslavement should not define a race of people. To others, slavery should be trumpeted as an example of what they did to us. … Rather than anonymous slaves, this exhibit introduces, and gives dimension to enslaved families like the Grangers, the Hemingses, Gilettes, the Herns and the Hubbards.  But the exhibition also exhibits quite clearly the impact of slavery on both the nation, and on Thomas Jefferson.”

One of the difficulties of studying slavery during Jefferson’s time is that historians lack the extensive documentary sources you might find when studying, say, Thomas Jefferson himself. Much of the inquiry at Monticello, Mount Vernon and Colonial Williamsburg for the last 40 years or so has sought to address that imbalance. For Rex Ellis, curatorial director at the museum, that is an opportunity; “they can help us to tell a more complete story, but there’s so little information generally that collaborating with a place like Monticello allows you to do so much more.”

“When I came to Monticello they had been researching slavery for more than 50 years and it had been featured in almost every aspect of our interpretation,” said Leslie Greene Bowman, president of the Thomas Jefferson Foundation. “So the logical next step was to bring all this history from 50 years to a national stage here in Washington.”

To say the least, the collaboration has been fruitful. The exhibit is filled with the detailed stories of six enslaved families at Monticello, illustrated by the tools they used, what limited written accounts as are available, and such information as can be gleaned from the meticulous record keeping of Jefferson himself, for whom those families were—regardless of any domestic comity—lines on a property ledger. The entrance is dominated by a figure of Jefferson, backed by a wall with the names of his 607 slaves.

By focusing on those enslaved families about whom the most information is available, the degree to which they forged lives apart from Jefferson stands out. What they all shared was an emphasis on faith, family, education, and civic engagement, said Ellis, recounting the ways the descendants of Monticello slaves became involved in political currents of the day including the Niagara Movement, politics in California and fighting for the Union during the Civil War.

“Once you look beyond 1826 and into these people’s life in freedom, you find out values and characteristics and skills and talents that were at Monticello as well,” said Dianne Swan Wright, who worked on the oral history of descendants of Monticello’s enslaved. “Peter Fawcett became a very prominent caterer, worked on the Underground Railroad, founded a church, 1500 people attended his funeral, and was a very prominent man in Cincinnati.  And he didn’t just appear out of nowhere, he came out of an extended family at Monticello.”

Of course, it’s impossible to talk about slavery at Monticello without addressing the Thomas Jefferson-Sally Hemings paternity question, about which there was much research and controversy around 1997 with the publication of Annette Gordon-Reed’s Pulitzer-winning book Thomas Jefferson and Sally Hemings: An American Controversy. The book’s publication mainstreamed the view that the two had an extended relationship, and their case was bolstered in 1998 when DNA testing proved that the descendants of Eston Hemings shared a Y chromosome with the males in Jefferson’s line.

The Thomas Jefferson Foundation concluded that the preponderance of evidence supported the idea that Jefferson fathered all of Hemings’ children, though a definitive answer is probably impossible to obtain, short of digging up the third President and testing his DNA. Rising to defend Jefferson, the Thomas Jefferson Heritage Society produced a report that came to the opposite conclusion, with scholars’ opinions ranging from “serious skepticism” to “almost certainly false.” Ironically, the night they released their findings to the National Press Club in 2001, President Bush was welcoming Hemings and Jefferson descendants at the White House to celebrate the anniversary of Jefferson’s birthday. Though the Scholars Commission identifies a lot of flaws in the argument for Jefferson’s paternity, it’s hard to escape the conclusion that it comes from a politicized body. The TJHS’s stated purpose is to “stand always in opposition to those who would seek to undermine the integrity of Thomas Jefferson,” and seek to “sponsor and perform research in matters pertaining to the private and public life of Thomas Jefferson.” In fact, the editor of the study is a professor of national security law, not a historian, which itself is evidence of the legalistic trench warfare that has ensued over the Jefferson-Hemings relationship.

I asked several of the Thomas Jefferson Foundation staff if they felt the TJHS study—which was finally published in book form last year—was somewhat tainted by the goals of its sponsoring organization, and the responses ranged from frank (“Yes.”), to coy, (“We’ll let your statement stand.”), to respectfully bureaucratic; “The foundation shares the belief of most historians that the preponderance of evidence; DNA, scientific, documentary and oral history, all help us conclude that Thomas Jefferson and Sally Hemings fathered children together. That group has looked at all the evidence and concluded differently.”

But even if we did dig him up, would proving Jefferson’s non-paternity really vindicate him at all? Is it possible to, as the Thomas Jefferson Heritage Society attempts, “further the honor and integrity” of someone who was engaged in industrial enterprise using human chattel labor? Who knows. But the question is about more than just deifying or defrocking a founding father for supposed miscegenation. A larger question, and one I think the exhibit gets at very well, is the degree to which Jefferson’s assumptions about American democracy rested on a fraudulent prosperity built on the backs of slaves.

“Directly or indirectly, the economies of all thirteen states depended on slavery,” said Ellis, noting that Jefferson’s own views were conflicted. “Slavery literally made the world the founders knew. But even though his livelihood depended on it, Jefferson opposed slavery, calling it an “abominable crime,” a “deplorable entanglement.” Early in his public life, he was one of the first statesmen to take action to end it. But after 1785, though he continued to hold his beliefs, he was publicly silent on the subject of slavery. Like many others of his day, such as James Madison, he eventually thought the best solution was gradual emancipation combined with colonization, or the return of freed slaves to Africa.”

Shannon Lanier, a descendent of Madison Hemings and author of Jefferson’s Children,was on hand at the exhibit opening. When I caught up with him next to a display of his family tree, he recounted a time when he tried to tell his family’s story in school. “I stood up in class and said ‘I’m related to Thomas Jefferson! He’s my great-great-great-great-great grandfather!’ And the teacher said, ‘sit down and stop telling lies.’”

“But we knew it to be true, it was our family story, just like you know who your grandparents are. That’s how I knew who my ancestors were, and I didn’t need the validation of the DNA because I already had that through my family story.”

What does he think about the new exhibit? “It’s a great peek into Monticello and Jefferson too. He didn’t build Monticello. The slaves did that. Who used these tools? It’s the reality of slavery and the reality of our country. Just because I’m related to Thomas Jefferson doesn’t make me that much different than tons, thousands of other African-American families. I think it’s finally time that they get that recognition, and the fact that it’s here at the Smithsonian is a wonderful opportunity for other people to get the conversation started.”