Lacy, they didn't all shut at once. Some held out for several years.
I don't know for sure, but Caval in Illinois may have been the last to close. If it wasn't, it was at least one of the last. 2007, maybe?
I'm sure that information can be found, if someone wanted to do a little research.
Just found this article. Apparently, Montana already has a law in place allowing equine slaughter plants to open. The article is from 2009: Montana OKs equine slaughter plants
National Report -- Montana now allows horse-processing plants to be built within its borders, and a handful of other states soon may do likewise in response to increasing numbers of unwanted and neglected horses in the declining economy.
The trend is happening even as the U.S. Congress continues to debate legislation that would prevent the sale, transport and slaughter of horses for human consumption.
The law permitting investor-owned equine processing facilities in Montana went into effect May 4 without the signature of Gov. Brian Schweitzer, whose efforts to have parts of the bill amended were rebuffed in the Legislature. Bills passed and not vetoed within 10 days automatically become law in Montana.
The governor offered amendments that would have removed two provisions from the bill - one that prevents state courts from issuing injunctions to stop or delay construction of a processing facility based on permit appeals or challenges, and another that requires objectors to submit a surety bond to the court.
Those provisions are aimed at the type of legal challenges that forced the 2007 closures of the nation's last horse-slaughter facilities, in Illinois and Texas.
Meanwhile, a North Dakota measure authorizing $75,000 for a study to determine whether a horse-processing facility would be economically viable in that state goes into effect in July.
South Dakota is debating a similar feasibility study.
In contrast, an Illinois legislator's attempt to have that state's ban on horse slaughter overturned failed to win enough votes in the state House.
In Tennessee, legislation that would allow private development of processing facilities and limit legal challenges was approved by the House Agriculture Committee and sent to the Senate Commerce Committee, but the panel adjourned before considering it. Its sponsor, Rep. Frank Niceley, says it will be taken up again in January 2010.
The federal legislation to ban horse sales, transport and slaughter for human consumption (H.B. 503 and S. 311) remains in committee, but several state legislatures have passed resolutions urging rejection of the legislation or instructing their delegations to vote against it.
Such resolutions recently passed in Arkansas, Kansas, Missouri, South Dakota, Utah and Wyoming, but failed in Georgia, Idaho and Minnesota. Resolutions are still under consideration in Tennessee and Arizona.
While the federal legislation and the states moving to allow slaughter facilities seem to be at odds, the sticking point could be the phrase "for human consumption." The federal legislation doesn't address horse slaughter for other purposes, so the question for states considering new plants might be whether they can make money processing animals for purposes other than human consumption.