It depends – on whether you consider the largest to be the organ with the most pipes, the most stops or the most manuals (keyboards).

The Atlantic City Auditorium organ is usually thought of as the largest in the world – 7 manuals, 449 ranks of pipes, 33,114 pipes including 9 32 foot ranks and a true (not acoustic ) 64 foot rank. However it is only partly functioning at the moment.

The Wanamaker Store organ in Philadelphia ( Macey’s ) has only 6 manuals and 28,522 pipes, but has more ranks – 463.

The U. S. Military Academy Chapel in West Point NY has the largest organ with drawstops (rather than stop tabs ) with 380 ranks and 23,500 pipes

An organ museum at ‘the House on the Rock ‘ Spring Vale Wisconsin houses several consoles, including an 8-manual console and a huge console with 15 manuals in three stacks of 5 each.

Visit http://www.die-orgelseite.de/kurioses_e.htm#spieltische for more information.