As of 2010 the Catholic Church had the highest number of adherents as a single denomination in the Boston-Cambridge-Newton Metro area, with more than two million members and 339 churches, followed by the Episcopal Church with 58,000 adherents in 160 churches. The United Church of Christ had 55,000 members and 213 churches. The UCC is the successor of the city's Puritan religious traditions. Old South Church in Boston is one of the oldest congregations in the United States. It was organized in 1669 by dissenters from the First Church in Boston (1630). Notable past members include Samuel Adams, William Dawes, Benjamin Franklin, Samuel Sewall, and Phillis Wheatley. In 1773, Adams gave the signals from the Old South Meeting House that started the Boston Tea Party.

Answer this question, if possible (if impossible, reply "unanswerable"): What Boston church is one of the oldest congregations in the US?
Old South Church