On this day, Aug. 23 ...

2008: Democratic presidential candidate Barack Obama introduces his choice of running mate, Sen. Joe Biden of Delaware, before a crowd outside the Old State Capitol in Springfield, Ill.

Also on this day:

1305: Scottish leader William Wallace is executed in London.

Scottish leader William Wallace is executed in London. 1914: Japan declares war against Germany in World War I.

Japan declares war against Germany in World War I. 1927: Italian-born anarchists Nicola Sacco and Bartolomeo Vanzetti are executed in Boston for the murders of two men during a 1920 robbery.

Italian-born anarchists Nicola Sacco and Bartolomeo Vanzetti are executed in Boston for the murders of two men during a 1920 robbery. 1939: Nazi Germany and the Soviet Union sign a nonaggression treaty.

Nazi Germany and the Soviet Union sign a nonaggression treaty. 1973: A bank robbery-turned-hostage-taking begins in Stockholm; the four hostages end up empathizing with their captors, a psychological condition now referred to as "Stockholm Syndrome."

A bank robbery-turned-hostage-taking begins in Stockholm; the four hostages end up empathizing with their captors, a psychological condition now referred to as "Stockholm Syndrome." 2000: Approximately 51.7 million people watch the season finale of the first season of “Survivor” on CBS.

Approximately 51.7 million people watch the season finale of the first season of “Survivor” on CBS. 2003: Former priest John Geoghan, a convicted child molester whose prosecution sparked the sex abuse scandal that shook the Roman Catholic Church nationwide, dies after another inmate attacks him in a Massachusetts prison.

2013: A military jury convicts Maj. Nidal Hasan in the deadly 2009 shooting rampage at Fort Hood, Texas, that claimed 13 lives.

2018: A long-running rift between President Donald Trump and Attorney General Jeff Sessions exploded into a public smackdown, with Trump accusing Sessions of failing to take control of the Justice Department and Sessions responding that he "will not be improperly influenced by political considerations."

A long-running rift between President Donald Trump and Attorney General Jeff Sessions exploded into a public smackdown, with Trump accusing Sessions of failing to take control of the Justice Department and Sessions responding that he "will not be improperly influenced by political considerations." 2018: The United States and China imposed tariff increases on an additional $16 billion of each other’s goods.