John Marshall Harlan the Elder is best known for his lonely judicial dissents in favor of civil rights for African-Americans, such as Plessy v. Ferguson in 1896. A life-long Calvinist Presbyterian, Harlan had come to understand the Civil War as part of God’s plan to free the nation from the sin of slavery. Borrowing the method of typology from Bible reading, Harlan saw the Civil War as following the type set by the American founders who had overthrown the tyranny of kings. A former slaveholder, Harlan retained the idea that Anglo-Saxons were particularly good at creating constitutional governments. Anglo-Saxonism prompted him to try to extend equal rights to his church’s Presbyteries and to the inhabitants of American colonies after the Spanish-American war, but to avoid talking about so-called social rights that involved inter-racial schooling and marriage. His philosophy of legal formalism could not solve the problems of logic that resulted.

Since the first settlements in British North America, Christianity and the Bible have had a significant influence on American jurisprudence. This reflects Christianity’s expansive influence on Western legal traditions in general and the English common law in particular. Christianity’s influence on American law was most pronounced in the colonial era, especially in New England’s Puritan commonwealths. Early colonial laws drew extensively from biblical sources, especially Mosaic law as interpreted within the colonists’ theological traditions. Christianity also contributed to an evolving constitutional tradition in the colonies and, later, the newly independent states, culminating in the U.S. Constitution framed in 1787. This is evident in broad principles, such as the separation of powers needed to check the abuse of government powers vested in fallen human actors, as well as in specific provisions such as the Article III, § 3 requirement that convictions for treason be supported by “the testimony of two witnesses” and the Fifth Amendment prohibition on double jeopardy. Although Christianity remained a dominant cultural force well into the nineteenth century and beyond, church-state separationists, secularists, and rationalists increasingly challenged its influence on law. This is seen, for example, in bitter political and legal controversies involving the Sunday mails, blasphemy laws, and the Bible’s invocation as authority in judicial proceedings. These disputes signaled Christianity’s declining influence in an increasingly secular age.