Pork barrel is a metaphor for the appropriation of government spending for localized projects secured solely or primarily to bring money to a representative's district. The usage originated in American English. In election campaigns, the term is used in derogatory fashion to attack opponents. However, scholars use it as a technical term regarding legislative control of local appropriations.
The term pork barrel politics usually refers to spending which is intended to benefit constituents of a politician in return for their political support, either in the form of campaign contributions or votes. In the popular 1863 story "The Children of the Public", Edward Everett Hale used the term pork barrel as a homely metaphor for any form of public spending to the citizenry. However, after the American Civil War, the term came to be used in a derogatory sense. The Oxford English Dictionary dates the modern sense of the term from 1873. Pork barrel originally came from storing meat. By the 1870s, references to "pork" were common in Congress, and the term was further popularized by a 1919 article by Chester Collins Maxey in the National Municipal Review, which reported on certain legislative acts known to members of Congress as "pork barrel bills". He claimed that the phrase originated in a pre-Civil War practice of giving slaves a barrel of salt pork as a reward and requiring them to compete among themselves to get their share of the handout. More generally, a barrel of salt pork was a common larder item in 19th century households, and could be used as a measure of the family's financial well-being. For example, in his 1845 novel The Chainbearer, James Fenimore Cooper wrote: "I hold a family to be in a desperate way, when the mother can see the bottom of the pork barrel."
Typically, "pork" involves funding for government programs whose economic or service benefits are concentrated in a particular area but whose costs are spread among all taxpayers. Public works projects, certain national defense spending projects, and agricultural subsidies are the most commonly cited examples.