At the time of its opening on October 10, 1790, the organ Tannenberg constructed at the Zion Church in Philadelphia was the largest in the United States and considered the best of its kind. The construction was 24 ft (7.3 m) feet across in the front, by feet deep, by 27 ft (8.2 m) high. The front row of metal pipes numbered 100. There were 2000 pipes in the body. The organ had five sets of keys. There was a fire in the church on December 26, 1794, which destroyed the building. The organ was destroyed, except for a few salvaged pipes. Tannenberg later wrote to a friend that, "On the main manual seven stops are now in place, and the pedal are complete, with the exception of five pipes in the Trombone Bass. The Echo is in place and completed. On the upper manual one stop, the Principal, is finished. When all is drawn out on the lower manual, with Pedal, the church is well filled with the volume of sound."