January 15 – Martin Luther King Day Crash – Telephone service in Atlanta, St. Louis, and Detroit, including 9-1-1 service, goes down for nine hours, due to an AT&T software bug.
In Washington, D.C., Mayor Marion Barry is arrested for drug possession in an FBI sting.
In California, the McMartin preschool trial, the longest criminal trial in U.S. history, ends with all defendants being acquitted on charges of child molesting.
In Miami, William Lozano, a Hispanic police officer, is sentenced to seven years in prison for shooting a black motorcyclist in 1989, an event that had set off three days of rioting.
President of the United States George H. W. Bush gives his first State of the Union address and proposes that the U.S. and the Soviet Union make deep cuts to their military forces in Europe.
February 14 – The Pale Blue Dot picture was sent back from the Voyager 1 probe after completing its primary mission, it was about 6 billion km (3.7 billion miles) from Earth.
Major League Baseball players and owners agree to a new four-year contract, ending the lockout begun on February 15.
March 22 – A jury in Anchorage, Alaska finds Joseph Hazelwood guilty of misdemeanor negligence for his role in the Exxon Valdez oil spill. He is sentenced to pay $50,000 in restitution and to spend 1,000 hours cleaning oily beaches.
March 25 – In New York City, a fire due to arson at an illegal social club called "Happy Land" kills 87.
April 6 – Robert Mapplethorpe's "The Perfect Moment" show of nude and homosexual photographs opens at the Cincinnati Contemporary Art Center, in spite of accusations of indecency by Citizens for Community Values.
April 7 – Iran-Contra Affair: John Poindexter is found guilty of five charges for his part in the scandal; the convictions are later reversed on appeal.
April 8 – Ryan White, who made headlines after being expelled for contracting AIDS, dies from the disease at the age of 18.
April 17–18 – President Bush meets with representatives of 17 countries and two international organizations at the White House to discuss global warming and other environmental issues.
April 30 – Lebanon hostage crisis: Lebanese kidnappers release American educator Frank H. Reed, who had been held hostage since September 1986.
May
May 13 – In the Philippines, gunmen kill two United States Air Force airmen near Clark Air Base on the eve of talks between the Philippines and the United States over the future of American military bases in the Philippines.
May 19 – The U.S. and the Soviet Union agree to end production of chemical weapons and to destroy most of their stockpiles of chemical weapons.
May 30 – President Bush and Mikhail Gorbachev begin a four-day summit meeting in Washington, D.C.
June
June – The last month of the 1980s business cycle expansion, at the time the second-longest expansion in American history (the 1960s expansion was a year longer), comes to an end; the unemployment rate is 5.2%.
The Dow Jones Industrial Average closes above 2,900 for the first time ever.
June 2 – The Lower Ohio Valley tornado outbreak spawns 88 confirmed tornadoes in Illinois, Indiana, Kentucky, and Ohio, killing 12; Thirty-seven tornadoes occur in Indiana, eclipsing the previous record of 21 during the 1974 Super Outbreak.
June 26 – President George H. W. Bush reneges on his 1988 "no new taxes" campaign pledge in a statement accepting tax revenue increases as a necessity to reduce the budget deficit.[1] This later becomes a factor in the 1992 presidential election.
August 18 – In New York City, a jury finds three teenagers guilty of raping and assaulting a woman in Central Park in April 1989. On September 11, they are sentenced to 5–10 years in prison.
September 8 – Fox Kids, a children's programming block, debuts on Fox.
September 9
President Bush and Soviet President Gorbachev meet in Helsinki to discuss the Persian Gulf crisis.
After six years of renovations, Ellis Island reopens as an immigration museum.
Pete Sampras, age 19, wins the 1990 US Open, becoming the youngest person to ever win the event.
September 11 – Gulf War: President George H. W. Bush delivers a nationally televised speech in which he threatens the use of force to remove Iraqi soldiers from Kuwait.
October 2 – The Senate confirms David Souter to the Supreme Court; he takes his seat on October 9.
October 3 – In Fort Lauderdale, Florida, a jury convicts a record store owner of obscenity for selling an album by 2 Live Crew. On October 20, a second jury finds 2 Live Crew not guilty of obscenity on charges stemming from a June 1990 performance.
October 5 – In Cincinnati, a jury finds an art museum and its art director innocent of breaking obscenity laws for displaying sexually explicit photographs by Robert Mapplethorpe.
October 6–8 – The federal government temporarily halts all non-essential services after Congress fails to enact a new budget and President Bush vetoes a stop-gap spending measure.
October 9 – Leonard Bernstein announces his retirement from conducting after 47 years. He dies five days later.[2]
President Bush vetoes a civil rights bill that would have strengthened federal protection against job discrimination, arguing that it would lead to race and gender-based quotas.
November 11 – Stormie Jones, the Texas girl who had been the world's first recipient of a simultaneous heart and liver transplant in 1984, dies at a Pittsburgh hospital at age 13.
December 2 – STS-35: Space Shuttle Columbia begins a mission that ends on December 10, a day earlier than planned, ending a mission plagued with computer and plumbing problems.
December 3 – At Detroit Metropolitan Airport, Northwest Airlines Flight 1482 (a McDonnell Douglas DC-9) collides with Northwest Airlines Flight 299 (a Boeing 727) on the runway, killing eight passengers and four crew members on Flight 1482.