the smithsonian national museum of african-american history and tracy polts goes behind the scenes to help tell the story. >> reporter: 13 years after congress approved it, the national museum of african- american history and culture opens this weekend. >> white, black, latino, our families have been here 200 years, or got here 20 minutes ago, this is a story that helps us better understand who we are as americans. >> reporter: there are nearly 4,000 artifacts here, some dating back to the 18th century. through slavery. segregation. and civil rights. then tuskegee airmen, the nation's first black military aviators. >> at a time when they weren't expected to be anything, they were more than anyone imagined. >> harriet tubman hymn book. rosa parks' dress, and louie armstrong's trumpet and muhammad ali's boxing gloves on display and many pioneers you may not know. >> the pacific parachute company was the first if not the only war production plant war ii. >> henry boyd bought his freedom and built a furniture factory. only to close after nearly 30 years because people repeatedly tried to