By some estimates, about 90 percent of African Americans can trace at least part of their ancestry to Charleston, South Carolina — at one time the most active slave-trading port in the country. The city will tell this part of its history — and look to its future — with the debut of the International African American Museum (iaamuseum.org) later this year. The focus spans centuries and continents, from the global impact of slavery and the diaspora to contemporary conversations about race and social justice. A permanent collection will be joined by rotating art exhibitions, community programming, and a genealogy lab, the Center for Family History. Here, a conversation with president and CEO Tonya M. Matthews.