: What Was #01 / Age of the Dinosaurs?
: What Was #03 / Battle of Gettysburg?
: What Was #04 / Boston Tea Party?
: What Was #05 / Ellis Island?
: What Was #06 / First Thanksgiving?
: What Was #08 / Great Chicago Fire?
: What Was #10 / Hurricane Katrina?
: What Was #12 / Lewis and Clark Expedition?
: What Was #14 / Pearl Harbor?
: What Was #16 / San Francisco Earthquake?
: What Was #17 / Underground Railroad?
: What Was #19 / Salem Witch Trials? (What Were)
: Where Is #02 / Easter Island?