If U.S. Vice President Kamala Harris has a favorite number on her trip to Africa, it's undoubtedly 19. That's the median age on this continent, and she repeats the fact at every opportunity.
For Harris, it's not a piece of trivia but the driving force behind the United States' reenergized outreach to Africa. Washington is racing to build partnerships on the oldest inhabited continent with the youngest population, a test that could reshape the economy here and, by extension, the rest of the world.
