Othniel Marsh and Edward Cope become bitter rivals while creating Paleontology and Penzias & Wilson discover the sound of The Big Bang.

Actor Clark Gable joins the U.S Air Force during World War II, Ponce de León quarrels with Diego Colón (son of Christopher Columbus) in the 1500s and Griselda Blanco takes over the cocaine trade in Miami in the 1970s.

Harriet Tubman provides military intel to the Union Army, Virginia Hall spies in France during World War II (and becomes the first woman in the C.I.A) and children's books' author Roald Dahl serves as a debonair British spy.

Wayne Wheeler leads the Prohibition charge, Dorothy Fuldheim paves the way for women in journalism, and Muhammad Ali refuses to fight in the Vietnam War.

Milton Bradley jumpstarts the board game industry, Roger Sharpe fights for pinball legalization in 1970s New York City, and Bobby Fischer becomes the World Chess Champion.

Kentucky Daisy claims land for the ladies, Gordon Cooper goes on a pioneering space mission, and former slave Bass Reeves becomes the inspiration for the Lone Ranger.

Nellie Bly and Elizabeth Bisland race each other around the world, New York's newsboys go on strike, and a political cartoonist exposes a corrupt politician.

The LAPD is formed to stop the city from devolving into chaos, Rin Tin Tin becomes a global superstar, and William Mulholland figures out how to bring water to Los Angeles.

Popé leads the Pueblo Revolt against Spanish colonizers in 1680, Boy Scouts cofounder Ernest Thompson Seton tracks a wolf, the true story of the Roswell UFO conspiracy is revealed.

Alexander Graham Bell beats Elisha Gray to the patent office for the telephone, Thomas Edison endeavors to launch a filmmaking monopoly.

Bugsy Siegel bets his life on a Las Vegas casino, while the Moulin Rouge breaks the color barrier, Sin City's origins are a popularity contest for J.T. McWilliams and William Clark.

Carl Sagan and Ann Druyan fall in love over a golden record, Wernher Von Braun pioneers rocket science, and Alexey Leonov becomes the first man to float in space.