In 1649 Maryland passed the Maryland Toleration Act, also known as the Act Concerning Religion, a law mandating religious tolerance for Trinitarian Christians only (excluding Nontrinitarian faiths). Passed on September 21, 1649 by the assembly of the Maryland colony, it was the first law requiring religious tolerance in the British North American colonies. The Calvert family sought enactment of the law to protect Catholic settlers and some of the other denominations that did not conform to the dominant Anglicanism of England and her colonies.