Paleontologists Othniel Marsh and Edward Cope become rivals, and Penzias and Wilson discover the echo of the Big Bang. Featuring Greg Kinnear, Stephen Merchant, Justin Long, Jason Ritter, Tony Hale and Christopher Meloni.

Actor Clark Gable joins the Air Force during World War II, Ponce de Leon quarrels with Diego Columbus, and Griselda Blanco takes over the cocaine trade in Miami.

Pirate John Lafitte helps Andrew Jackson defeat the British during the War of 1812, Sam Zemurray becomes a banana kingpin, and Louis Armstrong becomes a jazz legend. Featuring Jack McBrayer, Thomas Middleditch, Jason Momoa, Miles Brown and Andre Royo.

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 CIA, and Roald Dahl serves as a debonair British spy. Written by bridget

Wayne Wheeler becomes the face of Prohibition, Dorothy Fuldheim breaks barriers in news broadcasting, and Muhammad Ali refuses to fight in the Vietnam War.

Milton Bradley popularizes board games, Roger Sharpe helps overturn a pinball ban, and chess master Bobby Fischer defeats Russian rival Boris Spassky during the Cold War. Featuring Topher Grace, Zach Gilford, Taran Killam and Jake Johnson.

Kentucky Daisy stakes a claim to land, Gordon Cooper overcomes mechanical issues on a one-man space mission, and African-American Deputy Marshal Bass Reeves is the inspiration for the Lone Ranger. Featuring Kat Dennings, Colin Hanks and Jaleel White. Written by Bridget

Nellie Bly and Elizabeth Bisland try to travel around the world in under 80 days, and Thomas Nast's political cartoons lead to the downfall of Tammany Hall leader Boss Tweed. Featuring Michael Cera, Ellie Kemper, Natasha Leggero and Jason Alexander.

The Wild West origins of the LAPD, Rin Tin Tin's rise to fame as a Hollywood star, and the shady dealings behind the LA Aqueduct and St. Francis Dam. Featuring Giancarlo Esposito, Ryan Phillippe, Derek Waters, Jack Black, Kyle Gass, Zach Woods, and Rowdy, as Rin Tin Tin. Written by Pixie Sherry

Popé leads the Pueblo Indians in a revolt, Boy Scouts founder Ernest Thompson Seton tracks a wolf, and the truth behind the Roswell UFO conspiracy is revealed. Featuring Colin Hanks, Jason Mantzoukas, Rob Huebel, Tom Lennon and Patton Oswalt.

Alexander Graham Bell steals the original design for the telephone from Elisha Gray, and Thomas Edison tries to create a movie-making monopoly. Featuring Parker Posey, Chris Parnell, Jason Ritter, Martin Starr, Michael McKean and Henry Winkler.

J.T. McWilliams forms a community but is muscled out by William Clark, Bugsy Siegel bets his life on the Flamingo Casino, and the Moulin Rouge is the first casino to break the color barrier. Featuring Sam Rockwell, Donald Faison, and Dennis Quaid.

Carl Sagan and Ann Druyan fall in love, Wernher von Braun becomes the father of American rocket science, and Russian cosmonauts perform the first spacewalk.