Around midnight on March 24, 1989 the Exxon Valdez ran aground on Blight Reef in Prince William Sound near the Alaskan town of Valdez. The Exxon Valdez disaster would become the largest oil spill in U.S. history. Roughly 1/5 or 11 million gallons of crude oil was spilled before being successfuly transfered to another Exxon tanker. Nevertheless, the ecological and economical reprecussions were enormous.
Initially, the spill should have been easy to clean up as it was slow and was isolated to mainly deep water. However, the isolated region of Valdez, accessible only by ship or helicopter made the clean up difficult. Also, the captain, Joseph Hazelwood was found to be intoxicated and even attempted to ease the ship off the reef (Thankfully he was unsuccessful or the disaster could have been even worse.) before finally calling the United States Coast Guard for assistance obviously did not help the situation causing more oil to leak out than necessary.
However, the worst thing that happened was 3 days after the inital spill, a storm drove oil along 40 miles of Alaskan shoreline, shortly after a reluctant Exxon agreed to start clean up.
Clean up proceeded for several months, and even today one can go and still kickup some rocks and find crude oil from the Exxon Valdez. Among the methods of clean up for the oil slick were burning, mechanical cleanup,skimming, and chemical dispersants (This failed.). For the oil drenced wildlife and shoreline, handwashing, bacteria that degraded the oil, and high-pressured water to blast it off the rocks and skim the oil off.
The disaster cost Exxon more than $2 billion in clean up, lawsuits, and fines. Captain Hazelwood was fired (I believe he was also jailed on gross incompetence.). The Exxon Valdez is now in the Mediterranean under the name the Exxon Mediterranean. The disaster also led to the passage of the Oil Pollution Act of 1990.