Wilmington to Baltimore

S1 E106: On the Mason-Dixon line, Michael Portillo discovers the origins of what became, for black Americans, the border between slavery and freedom. He uncovers the explosive history of gunpowder in Delaware and then travels to Baltimore, home of the first railroad in the US. At Fort McHenry, he hears how the Star-Spangled Banner was born and learns what makes a Maryland crab cake so delicious.