* What Was D-Day? (What Was?) 

* What Was Ellis Island?  (What Was?)

* 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?)