MILLENNIUM NOTEBOOK: 1985-89

For 28 years, it stood as the Cold War's most visible divide a barrier of concrete and barbed wire separating the people and ideals of the East and West. It was a stunning event when, on a chilly November day in 1989, the Berlin Wall came tumbling down at the hands of thousands of East and West Germans, who clambered atop the rubble to celebrate.

On Jan. 28, 1986, the nation is horrorstruck when the shuttle Challenger explodes 73 seconds after takeoff from Kennedy Space Center. All seven crew members are killed.