Just over 75 years ago—on April 1, 1945—American troops invaded the 70-mile long island of Okinawa in the largest amphibious operation of the Pacific War.

Fox News Anchor and author Chris Wallace discusses his latest book, Countdown 1945: The Extraordinary Story of the Atomic Bomb and the 116 Days That Changed the World.

In this episode, we take a closer look at Lieutenant General Leslie Groves, director of the Manhattan Project. While a lot of interest is rightfully set on Oppenheimer, Groves proves to be an interesting character and pivotal player in the development of the bomb.

John Curatola, Samuel Zemurray Stone Senior Historian at the National WWII Museum, traces the history of the 'Bloody 100th' Bomb Group, the Eighth Air...

Learn more about this important breakthrough and some of the science behind it.