After President McKinley was shot, Teddy Roosevelt became president and the first to have round the clock protection by the Secret Service. But why did it take Congress 25 presidencies and three assassinations to make that happen?

As the Civil War teetered, Lincoln weighed the Emancipation Proclamation—an audacious act that reshaped the nation’s course.

Doris Kearns Goodwin shares how President Lyndon B. Johnson, despite fierce resistance, rose to meet a defining moment in U.S. history.

The top secret "nuclear football" accompanies the president at all times.