1638 – First Church and Parish in Dedham, Massachusetts, was organized on this date. This church, now Unitarian Universalist, was the focus of the Dedham Decision, a decision by the Massachusetts Supreme Court in 1820 that gave property rights to parishes rather than churches, changing a long-standing tradition and clearing the way for the new liberal Unitarianism that was emerging in the 1820s. Within 20 years, one-quarter of the Congregational churches in Massachusetts were Unitarian. Read more about the Dedham Decision here.