December 8, 1941: After a Japanese surprise attack on Pearl Harbor, the United States declares war on Japan and enters World War II. The war will continue until August 14, 1945.

Today: The United States is involved in several international conflicts, but has not officially declared war since 1941.

1941: The Brooklyn Dodgers baseball team wins the National League pennant, but loses the World Series to the New York Yankees. Red Barber is the baseball announcer for the Brooklyn Dodgers.

Today: The Dodgers now play in Los Angeles, where they moved in 1958. Most fans follow the games on television, which became popular in the 1950s.

1940s: In metropolitan areas like New York City, outerwear for businessmen includes gloves and formal hats, usually of felt, with creased crowns and narrow brims that go all the way around.

Today: Businessmen usually are seen without hats of any kind, except in severe weather...