Ixtoc I was an oil rig off the coast of Mexico in the eponymous Gulf Thereof. In 1979-80, it blew and spewed what has been until this point the largest amount of oil ever released into the Gulf in a single event.
And it may still be the biggest ever. No one knows for sure how much goo the BP spill is spilling, but the high-end estimates would only in the next few days put the total above the Ixtoc I spill.
So, why have you and we never heard of Ixtoc I, while we've heard of Exxon Valdiz and Santa Barbara and such? Well, silly, Ixtoc I affected Mexico, so it doesn't matter.
This phenomenon is utterly common and predictable, of course. Influential people, meaning rich people, object to environmental impact that is nearby. They're oblivious to the same when it is far away.
So it's fine to drill in the Middle East but not in the USA. The biggest spill ever was in the Persian Gulf, by the way, where our former friend Saddam deliberately dumped a half billion gallons during the 1991 war.
Closer to home this NIMBY phenomenon works as well. It's fine to drill off the coast of benighted Southern states, but not off the prestigious Atlantic or Pacific coastlines, where the movers and shakers move and shake.
We'll opine that the worst of this is that there's been no public discussion of the effect of these previous spills on the ecosystems of their regions or significant citation of lessons learned from such episodes (see only the forward-looking remark of a Coast Guard Commander cited at the end of the article linked above). There's only hand-wringing and favor-begging and political posing by political poseurs. We'd rather blame and profit than learn and solve.