Saint Louis Cathedral has an interesting history associated with it's Grand Organ. According to material supplied through the Organ Historical Society, the first documented organ installed there was a Henry Erben instrument installed circa 1850. In 1870, a 2 manual Pilcher instrument.was purchased to replace the Henry Erben organ. In the 1930's, the Austin firm installed their Opus 868, a 3 manual, 14 stop organ. In the 1950's, the M.P. Moller Company installed their Opus 8158 which was a 76 stop, 3 manual organ. In 1967, builder Otto Hoffman performed modifications and upgrades which rendered a 3 manual, 58 stop instrument which was composed principally of pipe work and the console from Moller Opus 8158. In 2002, the Holtkamp firm, under funding provided by then retired music director Dr. Elise Cambon, produced a 77 stop organ, complete with a 3 manual terraced console. Much of that organ was based on the original Moller / Hoffman instrument with major modifications and rebuilds by the Holtkamp firm.

When Hurricane Katrina struck, the Holtkamp organ sustained damage. It was completely removed from the church and two years later, a new Holtkamp instrument was delivered and installed. That is the present instrument at the Cathedral