1940s: A number of authors naturally turn to World War II for their subject matter. Books such as Ilya Eherenberg's The Fall of Paris, Ernie Pyle's Here Is Your War, and Ted Lawson's Thirty Seconds over Tokyo brought the complexities of the war into the libraries of millions.

Today: World War II is still a widely-discussed era that has inspired a number of important works of fiction and nonfiction, including Thomas Pynchon's Gravity's Rainbow, Stephen Ambrose's Citizen Soldiers, and Tom Brokaw's The Greatest Generation.

1940s: After World War II ends, the East German Social Democrats merge with the Communists, eventually leading to the division of Germany into East and West, and the construction of the Berlin Wall in 1961.

Today: Largely due to the actions of U.S. President Ronald Reagan and Soviet President Mikhail Gorbachev, the Berlin wall has been destroyed (1989) and the two...