Milestones

Ten years ago: The Soviet Union began the process of withdrawing its troops from Afghanistan, more than eight years after Soviet forces had entered the country.

Five years ago: Bosnian Serbs began voting in a two-day referendum that overwhelmingly rejected a U.N.-backed peace plan. Prairie Bayou won the Preakness.

One year ago: Space shuttle Atlantis blasted off on a mission to deliver urgently needed repair equipment and a fresh American astronaut to Russia’s orbiting Mir station.