51 Pa.C.S. § 4501
The Commonwealth of Pennsylvania does hereby join, approve and become a party to a solemn compact with the State of New Jersey and the State of New York and any other state concurring therein or otherwise approving thereof, in form and terms as heretofore agreed to by the Governor of the State of New Jersey and the Governor of the State of New York and approved by the respective Legislatures thereof, as follows:
An Interstate Compact For Mutual Military Aid
In An Emergency.