His career in the antislavery cause, dating from the Missouri Compromise in 1821, was in several respects unique, and among the leaders of the movement his position continued to be distinctive. His first active efforts in favour of the slave, the presentation to Congress in 1826 of petitions for the abolition of slavery in the District of Columbia, were marked by a careful regard to the provisions of the United States Constitution. At the first formation of antislavery societies he feared that philanthropic enthusiasm might place the movement in a wrong position by a failure to recognize those provisions. His advice was asked by the men who organized the American Society in Philadelphia, and it was carried into effect by the insertion into the constitution of the society of a complete recognition of the supreme national law, in strict accordance with which, only, the objects of the society should be sought. To maintain the abolitionists in the impregnable position thus adopted was the constant and characteristic labour of Jay's life. This position, consistently held by him against unconstitutional doctrines advanced by both abolitionists and slaveholders, was the position adopted by the Republican party in 1854, and maintained until real union and real liberty were won together. The antislavery movement was begun and supported by those whom Lincoln called "the plain people." Men of "property and standing" were generally passively if not actively hostile. It received little help from the churches, from the learned professions or the wealthy mercantile classes. It was a very unpopular cause, denounced by politicians, merchants, and lawyers, despised by many of the clergy, certain to bring social and business injury, if not active persecution, to whomsoever adopted it. Hence the championship of William Jay derived a special importance. His judicial and social position, his independent means, his active membership in the most aristocratic of churches, made him a leader of peculiar value. His advocacy of the cause could be attributed neither to ignorant fanaticism nor to disorganizing tendencies. He set an example to the class most able and least willing to oppose the curse of slavery.