The international race to develop biological weapons during the 20th century.
The effort of pioneering researchers to conceive babies through in vitro fertilization.
During the Great Depression, Americans built the Hoover Dam, one of the greatest engineering works in history.
The U.S. and the Soviet Union race to build the hydrogen bomb during the Cold War, thus beginning the nuclear arms race.
George Eastman introduced the Kodak and Brownie camera systems and transformed photography into something anybody could do.
Brothers Wilbur and Orville Wright built a flying machine that made its first flight in Kitty Hawk, North Carolina in 1903.
"The Wizard of Menlo Park," Inventor Thomas Edison, built the first practical light bulb and revolutionized the world.