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* What Was Hurricane Katrina? (What Was?)
* What Was Pearl Harbor? (What Was?)
* What Was Pompeii? (What Was?)
* What Was the Age of Exploration? (What Was?)
* What Was the Age of the Dinosaurs? (What Was?)
* What Was the Alamo? (What Was?)
* What Was the Battle of Gettysburg? (What Was?)
* What Was the Berlin Wall? (What Was?)
* What Was the Bombing of Hiroshima? (What Was?)
* What Was the Boston Tea Party? (What Was?)
* What Was the Gold Rush? (What Was?)
* What Was the Great Depression? (What Was?)
* What Was the Ice Age? (What Was?)
* What Was the Lewis and Clark Expedition? (What Was?)
* What Was the March on Washington? (What Was?)
* What Was the Underground Railroad? (What Was?)
* What Was the Vietnam War? (What Was?)
* What Were the Salem Witch Trials? (What Was?)
* What Are the Paralympic Games? (What Was?)
* What Are the Summer Olympics? (What Was?)
* What Is Climate Change? (What Was?)
* What Is Congress? (What Was?)
* What Is LEGO? (What Was?)
* What Is NASA? (What Was?)
* What is the Panama Canal? (What Was?)
* What is the Statue of Liberty? (What Was?)
* What Is the World Series? (What Was?)