Mayhew v. Thatcher et al. was a landmark case in which the Supreme Court of the United States established that state courts had jurisdiction over cases involving federal law and could issue writs of mandamus to compel officers of the United States to perform their duties under such laws. The case arose when Thomas Mayhew, an officer in charge of collecting revenue from vessels entering Boston Harbor, sued several individuals for refusing to pay customs duties on goods they had imported into Massachusetts without paying them first at another port as required by federal law. In its decision, the court held that although Congress has exclusive authority over foreign commerce and navigation between states, it does not have exclusive power over all matters related thereto; rather, state courts may exercise concurrent jurisdiction with respect to certain aspects thereof so long as they do not conflict with any act or regulation passed by Congress concerning those matters. Furthermore, since no congressional statute prohibited state courts from issuing writs of mandamus against federal officers who failed to comply with their legal obligations under applicable statutes or regulations governing foreign commerce and navigation between states (as was alleged here), then such writs were permissible even though issued by a state court instead of a federal one.

In Mayhew v. Thatcher et al., the Supreme Court was asked to decide whether a state court had jurisdiction over an action brought by a citizen of another state against citizens of the same other state in which it sat. The majority opinion held that such jurisdiction did not exist, and Justice Story wrote a dissenting opinion arguing that states should have concurrent jurisdiction with federal courts when it comes to suits between citizens of different states. He argued that this would be consistent with the spirit and letter of Article III, Section 2, Clause 1 of the Constitution which grants Congress power “to make all laws necessary for carrying into execution” its judicial powers. Furthermore, he noted that if one party is unable or unwilling to bring suit in their home state due to bias or prejudice then they should still have access to justice through another forum like a foreign court where both parties are treated equally under law regardless of citizenship status. Finally, he concluded his dissent by noting how important it is for individuals who are wronged by others from out-of-state jurisdictions have recourse available outside their own borders so as not be denied justice simply because they cannot travel far enough away from home for relief