How did pork barrel spending get that name, and around when?

Found this at Answers.com:

"Origin: 1909

As an actual container for storing pig meat in brine, the pork barrel has been with us since the early days of the Republic. It seems to have been a measure of present and future prosperity. A farmer's almanac of 1801 urges readers to "mind our pork and cider barrels." A midcentury author states, "I hold a family to be in a desperate way, when the mother can see the bottom of the pork barrel." "I know our crops will be short next season," declares another almanac, "for the brine has all leaked out of the pork barrel!"

In the twentieth century, modern refrigeration made the actual pork barrel obsolete. But it took on new life in referring to political bills that bring home the bacon to a legislator's district and constituents. Pork had been used at least since the 1870s as a label for politically motivated federal funding for local projects like post offices. We read in the Congressional Record in regard to an 1888 rivers and harbors appropriation, "Has the pork been so cunningly divided amongst the members of the House in this bill that its final passage is assured?"

By 1909, pork barrel itself was making the rounds of Congress. An article that year explains that the Democratic Party "has periodically inveighed against the extravagance of the administration, but its representatives in the Legislature have exercised no critical surveillance over the appropriations. They have preferred to take for their own constituencies whatever could be got out of the congressional 'pork barrel.'" Similarly, an article in 1916 opposing a "trend towards national defense on the basis of the State militia" argues that it is "a triumph for the pork-barrel."

Even without ever having seen an actual pork barrel, we continue to use the term today for its vivid negative implications. A pork barrel suggests fat and grease, not only in its contents but also in those who reach for it."