The international race to develop biological weapons during the 20th century, the challenges scientists faced, and the moral dilemmas posed by their eventual success.
In the early 1830s, Texas, ruled by Mexico, held 20,000 U.S. settlers and 4,000 Mexican Tejanos, forcing residents to pick sides.
The grave truth behind modern forensics was discovered in 1920s New York.
Major Walter Reed's discovery in 1900 that mosquitoes spread yellow fever halted an outbreak and led to the disease's eventual eradication.
Robert Moses fueled some of the most ambitious -- and controversial -- public works projects ever conceived.
Engineer James Eads tamed the mighty Mississippi, turning New Orleans into the second largest port in the nation.
A brilliant scientist, Oppenheimer was tasked with the development of the atomic bomb during World War II.
The unusual life of David Vetter, who lived permanently inside a germ-free environment due to severe combined immunodeficiency.
While the U.N. debated strategies for control of atomic energy, the U.S. Navy was preparing for nuclear tests on Bikini Island.