The Boston King's Chapel adopts James Freeman's revised prayer book, without the Nicene Creed, establishing it as the first Unitarian congregation in the United States.

King's Chapel is an American independent Christian unitarian congregation affiliated with the Unitarian Universalist Association that is "unitarian Christian in theology, Anglican in worship, and congregational in governance." It is housed in what was for a time after the Revolution called the "Stone Chapel", an 18th-century structure at the corner of Tremont Street and School Street in Boston, Massachusetts. The chapel building, completed in 1754, is one of the finest designs of the noted colonial architect Peter Harrison, and was designated a National Historic Landmark in 1960 for its architectural significance. The congregation has worshipped according to a Unitarian version of the Book of Common Prayer since 1785, currently in its ninth edition.

James Freeman was an American Unitarian clergyman and writer, "noteworthy as the first avowed preacher of Unitarianism in the United States". After graduating Harvard and becoming pastor of King's Chapel in Boston, Freeman's revised Book of Common Prayer was adopted by the congregation. This and Freeman's later ordination are credited as the origins of Unitarianism in New England. Later receiving a D.D. from Harvard Divinity School, he was also a founding member of the Massachusetts Historical Society.

Since the 18th century, there have been several editions of the Book of Common Prayer produced and revised for use by Unitarians. Several versions descend from an unpublished manuscript of alterations to the Church of England's 1662 Book of Common Prayer originally produced by English philosopher and clergyman Samuel Clarke in 1724, with descendant liturgical books remaining in use today.

June 19 is the 170th day of the year in the Gregorian calendar; 195 days remain until the end of the year.