Though first seen only as an expensive luxury, Alexander Graham Bell's telephone soon transformed American life and became a necessity.
The international race to develop biological weapons during the 20th century.
Robert Moses fueled some of the most ambitious -- and controversial -- public works projects ever conceived.
Brothers Wilbur and Orville Wright built a flying machine that made its first flight in Kitty Hawk, North Carolina in 1903.
Engineered by William Barclay Parsons, the 21-mile, four-track route of the New York City Subway was the largest public works project in history.
While the U.N. debated strategies for control of atomic energy, the U.S. Navy was preparing for nuclear tests on Bikini Island.
The most daring and innovative accomplishment at the turn of the 20th century.