Washington, D.C.: L'Enfant's plan, the 1814 fire and a marble obelisk

Washington, D.C. was planned on paper before a single road existed — a capital built from scratch on a riverbank. This quiz invites you to explore its history in 20 questions with pictures.

What deal, struck over a dinner, decided where the capital would go, and where does the name «Columbia» come from? Who finished the city's plan once its French designer was gone, and why do historians doubt a famous legend about Benjamin Banneker? Why do some of the oldest markers of the capital stand in Virginia?

Then the house on Pennsylvania Avenue and the summer of 1814: who first lived in the mansion, where its name really comes from, what ended the fires the invaders lit, how the lost library was replaced and who carried off a famous portrait. Why did the great obelisk stand unfinished for years, why does its color change partway up, and what is its tiny tip made of? What is the dome really made of, and what headgear was refused for the bronze figure on top?

And more: an Englishman who left his fortune to a country he never saw, cherry trees with a troubled start, the meaning of 36 columns, a rule about building heights that almost everyone gets wrong, and a law of 1862. The pictures are old photographs, photochroms, engravings, watercolors, maps and a portrait in the public domain.