BP will have up to six years to pay the money it agreed to as part of the settlement. Most of that money -- $2.4 billion -- will go to the National Fish & Wildlife Foundation, an independent not-for-profit conservation group chartered by Congress in 1984. It is a windfall for the group, whose total contributions and commitments since its founding are just above $2 billion.

Another $350 million will go to the National Academy of Science.

BP identified the remaining $1.256 billion of the settlement as a "criminal fine." More than $1 billion of that fine will go to the U.S. Coast Guard's Oil Spill Liability Trust Fund, to be available for cleanup -- and compensation for those affected by -- oil spills in the Gulf .

It is single largest criminal fine on record. The previous record was $1.195 billion criminal fine paid by Pfizer as part of a $2.3 billion settlement in September 2009 over the fraudulent marketing of anti-inflammatory arthritis drug Bextra.

--CNNMoney's Mark Thompson and CNN's David Ariosto contributed reporting to this article.