…The cornerstone of St. John’s was set on September 14, 1815.
St. John’s first service was held on October 27, 1816, and
the church was consecrated on December 27, 1816.
Beginning with James Madison, until the present, every person who has held the office of President of the United States has attended a service at St. John’s. Several early Presidents were communicants, as were more recent ones. Thus, St. John’s is known as “the Church of the Presidents” and is registered as a National Historic Landmark.Pew 54 is the President’s Pew, and is reserved for the President’s use when in attendance at the church.
https://stjohns-dc.org/welcome-to-saint-johns-church/history/