Under the Fourteenth Amendment due process clause a state may not abrogate the rights of parties beyond its borders having no relation to anything done or to be done within them if what is done is not against the law or public policy of the state. Application of forum state's substantive law is unconstitutional absent significant contacts between the forum state and the litigation.
The mere recognition by the courts of one State that parties by their conduct have subjected themselves to certain obligations arising under the law of another State is not to be deemed an extra-territorial application of the law of the State creating the obligation. See Barnhart v. American Concrete Steel Co., 227 N. Y. 531, 535; 125 N. E. 675, denying recovery in a common law action for damages in the state of injury, on the ground that the employee's remedy was for compensation under the law of the state of employment. Compare In re Spencer Kellogg & Sons, 52 F.2d 129, 134, reversed on other grounds, 285 U.S. 502. Compensation was similarly denied in Hall v. Industrial Comm., 77 Colo. 338, 339; 235 Pac. 1073; Hopkins v. Matchless ...