1969 – A Union Oil Co. drilling rig in the Santa Barbara Channel, six miles offshore from Santa Barbara, California, suffered a blowout spilling 3 million gallons of oil.
1976 – The Argo Merchant ran aground southeast of Nantucket Island, Massachusetts, spilling 7.7 million gallons of fuel oil.
1979 – Exploratory well IXTOC 1 blew out in Mexico's Bay of Campeche in the Gulf of Mexico, 600 miles south of Texas. It took nine months to cap the well, during which time 140 million gallons of oil were released into the Gulf of Mexico. This is 14 times as much oil as was spilled by the Exxon Valdez in 1989. Oil reached as far as Texas beaches.
1989 – The Exxon Valdez ran aground, spilling 10 million gallons of oil into Prince William Sound, causing — to date — the worst oil spill in U.S. history.
1990 – The Mega Borg spilled 5.1 million gallons of oil in the Gulf of Mexico, 57 miles south-southeast of Galveston, Texas, following a pump-room explosion and fire.
1993 – The Bouchard B155, Balsa 37, and Ocean 255 collided in Tampa Bay, causing the Bouchard to spill 336,000 gallons of No. 6 fuel oil.
2000 – The Westchester ran aground near Port Sulphur, Louisiana, dumping 567,000 gallons of crude oil into the lower Mississippi River.
2004 – The M/V Selendang Ayu ran aground, spilling 337,000 gallons of oil in the Makushin and Skan bays in Alaska’s Aleutian Islands.
2005 – The U.S. Coast Guard estimated that more than 7 million gallons of oil were spilled in the Gulf of Mexico and near-shore areas from multiple sources due to Hurricane Katrina.
2006 – Seventy-one thousand barrels of waste oil spilled from a CITGO refinery on the banks of the Calcasieu River, Louisiana.
2008 – A barge carrying 419,000 gallons of heavy fuel collided with a 600-foot tanker in the Mississippi River, near New Orleans. Hundreds of thousands of gallons of fuel were spilled.
2009 – A 458-foot vessel struck a barge in the Houston Ship Channel, spilling 10,500 gallons of oil. In the same year, a supply vessel collided with a Liberian oil tanker, 40 miles offshore of Galveston, Texas, causing 18,000 gallons of oil to spill.
January 2010 – The Eagle Otome collided with a barge in the Sabine-Neches Waterway, near Port Arthur, Texas, spilling 462,000 gallons of oil.
April 6, 2010 – A pipeline owned by Cypress Pipe Company — a joint venture between Chevron and BP — broke, spilling 18,000 gallons of oil into the Delta National Wildlife Refuge in Louisiana.
April 20, 2010 – British Petroleum’s Deepwater Horizon, a semi-submersible drilling rig, suffered an explosion and fire, sinking on April 22. Eleven people were killed. The wellhead began leaking oil, and the riser (a 5,000-foot-long pipe connecting the wellhead to the rig) detached, leaking millions of gallons of oil. Automatic and manual efforts to sever and seal the well failed, and experts estimated it could take three months or longer to drill an adjacent pressure relieving well, during which time the spill could become not only the worst oil spill in U.S. history, but the worst industrial accident.