AP World History Unit Outlines Click on the time period you want to see. UNIT 1 - Foundations (8000 BCE - 600 CE) UNIT 2 - Post-Classical Era (600 - 1450) UNIT 3 - Early Modern Era (1450 - 1750) UNIT 4 - Modern Era (1750 - 1914) UNIT 5 - 20th Century (1914 - Present)