On January 28, 1969, a blowout on a Unocal rig six miles off the coast of California spilled three million gallons of oil into the waters off Santa Barbara.
The blackened beaches and oil-soaked birds and seals became icons for the environmental movement and eventually brought oil exploration off the Atlantic and Pacific coasts of the United States to a halt.
Now, President George W Bush, Republicans in Congress and big oil companies want to reopen those waters to oil and gas exploration.
In his radio address last Saturday, Bush said that "technological advances have allowed us to explore oil offshore in ways that protect the environment" and that outer continental shelf areas now off limits "could produce enough oil to match America's current production for almost 10 years".
The issue has become a dividing line for the presidential candidates. Republican Sen John McCain reversed his position last month and endorsed expanded offshore drilling, while Democratic Sen Barack Obama wants to maintain the moratorium on offshore drilling, which he says would do nothing to immediately lower gasoline prices.
In the past week, congressional Republicans have issued a blizzard of statements pushing for action before summer recess, and some Democrats may be leaning their way.
Polls show that Americans, pressed by high gasoline prices, may be open to offshore drilling. In a May Gallup poll, 57 per cent of people surveyed were willing to allow drilling in coastal and wilderness areas currently off limits, if it had the potential to reduce high gas prices.
But prying open US waters for oil and gas drilling remains a daunting political task. Real estate developers and tourism industries oppose drilling offshore.
Environmentalists are battling against it. Most Democrats in Congress oppose it, too. And for years, Florida politicians, including the president's brother, former Florida Governor Jeb Bush, have fought against drilling.
Compromise
Two years ago, a massive drive to expand offshore drilling ended with a compromise that opened an additional 8.3-million-acre area in the Gulf of Mexico known as Lease 181 and gave a chunk of the federal revenue to state governments.
Although the drilling would be in federal waters, state governments would have to give approval for exploration and production off their shores.
McConnell's legislation would give states an incentive to allow drilling by giving them a 37.5 per cent share of federal royalties.
Republicans have tried to link offshore drilling to the surge in gasoline prices.
"The American people are saying loud and clear - there is no ambiguity about it - they want us to do something about it, and they understand the laws of supply and demand," McConnell said last week. He said he was negotiating with Senate Majority Leader Harry M Reid in an effort to find common ground.
Top Senate Democrats this week said compromise was possible, but House Majority Leader Steny H Hoyer, a Democrat, issued a release saying that there are already 68 million acres of public lands and waters open for drilling.
The area is equal, he said, to Maine, New Hampshire, Vermont, Massachusetts, Connecticut, Rhode Island, New York, New Jersey, Delaware and about two-thirds of Maryland, combined.
The debate over offshore drilling has been muddied by a variety of claims about how much oil and gas might lie under the sea, what it would take to get hold of it and what the impact would be.
