One of the oldest surviving six-column engines is a small engine of 1820, possibly by Boulton & Watt, preserved at the Birmingham Museum of Science and Industry [REF].
Six-column engines were not usually built outside the UK, although at least one was built by the US West Point Foundry in the 1840s and exported to the Hacienda Azucarera La Esperanza in Puerto Rico, to drive a sugar cane mill.