From Chicago Lawyer Magazine:

It was Dec. 21, 2009, when Michigan Attorney General Michael A. Cox launched his legal battle with Illinois over Asian carp, but a much older date appeared on Page 1 of his motions. “In the Supreme Court of the United States,” the documents read – “October Term, 1966.”

It wasn’t a typo. Cox was asking the U.S. Supreme Court to reopen an old, old case. During that 1966 term, the Supreme Court issued a decree, limiting how much water runs out of Lake Michigan into the Chicago and Calumet rivers, flowing down canals toward the Illinois and Mississippi rivers – a flow known as “the Chicago Diversion.”

Now, Cox wants the Supreme Court to revisit that decree – as a way of blocking voracious Asian carp from getting into the Great Lakes through Chicago’s canals and rivers.

But that 1966 date only hints at the epic duration of this litigation. This case began in 1922, when Wisconsin sued Illinois, blaming the Chicago Diversion for lowering the water level of the Great Lakes. The same case has come up time and again at the Supreme Court for almost eight decades. Read more.