In 2000, Vermont Gov. Howard Dean signed the nation’s first bill allowing same-sex couples to form civil unions. Ten years ago: Robert Steinhaeuser, an expelled student, went on a shooting rampage at a school in Erfurt, Germany, killing 16 people, plus himself. David Gunn, who had run transit systems in New York City and Washington, was named president of Amtrak, the troubled national rail passenger service.

Five years ago: The Senate joined the House, 51-46, in clearing legislation calling for the withdrawal of U.S. troops from Iraq to begin by Oct. 1, 2007, with a goal of a complete pullout six months later (President George W. Bush later vetoed the measure). Eight Democratic presidential hopefuls gathered in Orangeburg, S.C., for their first debate of the 2008 campaign, during which they heaped criticism on President Bush’s Iraq policy. Former White House aide and movie industry lobbyist Jack Valenti died in Washington, D.C., at age 85.