ex post facto law

In 1966 the Pennsylvania Legislature enacted the Bituminous Mine Subsidence and Land Conservation Act to address land subsidence caused by underground coal mining. The Act authorizes the Department of Environmental Resources to implement and enforce a comprehensive program preventing or minimizing subsidence and consequent damage to surface structures. Section 4 prohibits mining that causes subsidence damage to public buildings, dwellings used for human habitation, and cemeteries, and generally requires that 50 percent of the coal beneath such structures remain in place to provide surface support. Petitioners are an association of coal producers and several of its member corporations engaged in underground bituminous coal mining in western Pennsylvania. They own, lease, or control substantial coal reserves and associated support estates beneath surface properties affected by the Subsidence Act. Many of these interests were severed from the surface estate between 1890 and 1920, and petitioners or their predecessors typically acquired waivers of liability for subsidence damage along with rights to deposit wastes, provide drainage and ventilation, and erect surface facilities. In 1982 petitioners filed a civil rights action in the United States District Court for the Western District of Pennsylvania against the Secretary of the Department of Environmental Resources and other officials. They sought to enjoin enforcement of the Subsidence Act and its implementing regulations, alleging that Section 4 and Section 6 effected a taking of their property without compensation and that Section 6 impaired their contractual obligations. The parties entered a stipulation of facts concerning the facial challenge and filed cross-motions for summary judgment. The District Court granted summary judgment in favor of the Department officials. The Court of Appeals for the Third Circuit affirmed. The Supreme Court granted certiorari to consider the constitutional challenges to the Subsidence Act. Petitioners have never claimed that the Subsidence Act makes it commercially impracticable for them to continue mining their bituminous coal interests in western Pennsylvania, nor have they identified any specific mine rendered unprofitable by the statute. The evidence in the record shows that enforcement of the 50 percent rule has required petitioners to leave less than 27 million tons of coal in place. This applies across 13 mines containing over 1.46 billion tons. It amounts to less than 2 percent of the total coal in those operations.

Dred Scott, along with his wife Harriet and their two children Eliza and Lizzie, was held as a slave by the defendant John F. A. Sandford in the State of Missouri. Scott initiated an action in the Circuit Court of the United States for the District of Missouri asserting his and his family's right to freedom. The declaration averred that Scott was a citizen of Missouri and the defendant a citizen of New York to establish diversity jurisdiction. The defendant responded with a plea in abatement asserting that the court lacked jurisdiction because Scott was not a citizen of Missouri. Scott was a negro of African descent whose ancestors were of pure African blood and had been brought into the country and sold as slaves. Scott demurred to this plea. The Circuit Court overruled the plea and required the defendant to answer over. The defendant then filed pleas in bar. After a trial on the merits the jury returned a verdict in favor of the defendant, leading to judgment for him. Scott then prosecuted a writ of error to the Supreme Court. The underlying facts showed that Scott had been the slave of Dr. Emerson, a surgeon in the United States Army. In 1834 Emerson took Scott from Missouri to Rock Island in Illinois, where he held him as a slave until 1836. Emerson then removed Scott to Fort Snelling in the Territory of Upper Louisiana north of thirty-six degrees thirty minutes north latitude, holding him there until 1838. Harriet, originally the slave of Major Taliaferro, was also brought to Fort Snelling and sold to Emerson. Scott and Harriet were married at Fort Snelling in 1836 with Emerson's consent, and their children were born there or during the return journey. In 1838 Emerson brought the family back to Missouri, where they resided until Emerson sold them to Sandford. The case reached the Supreme Court after two arguments. The Court ordered reargument on some of the points due to differences of opinion among the justices and the importance of the questions involved.

In 1998 Congress enacted the Copyright Term Extension Act, which extended the duration of all federal copyrights by twenty years. For works created by identified natural persons the new term runs from creation until seventy years after the author's death. For anonymous works, pseudonymous works, and works made for hire the term is ninety-five years from publication or one hundred twenty years from creation, whichever expires first. The statute applied these extended terms both to copyrights already in existence and to works created after its effective date. Petitioners are individuals and businesses whose products or services build on copyrighted works that have gone into the public domain. They filed suit in the United States District Court for the District of Columbia seeking a declaration that the extension of existing copyrights exceeded Congress's power under the Copyright Clause and violated the First Amendment. On cross-motions for judgment on the pleadings the district court entered judgment for the Attorney General. The Court of Appeals for the District of Columbia Circuit affirmed. A majority of the panel upheld the statute against both challenges, while Judge Sentelle dissented in part on the Copyright Clause issue. The Supreme Court granted certiorari to address whether the extension of existing copyrights exceeds Congress's power under the Copyright Clause and whether the extension violates the First Amendment.