Era 1: Our Big History (13.82 billion years ago to the future)
52 Questions
Era 2: Early Humans (250,000 years BP to 3,000 BCE)
64 Questions
Era 3: Cities, Societies, and Empires (6,000 BCE to 700 CE)
156 Questions
Era 4: Regional Webs (200 to 1500 CE)
69 Questions
Era 5: The First Global Age (1200 to 1750 CE)
82 Questions
Era 6: The Long Nineteenth Century (1750 to 1914 CE)
Era 7: The Great Convergence and Divergence (1880 CE to the future)
125 Questions
