When first flown in 1941, the Douglas XB-19 was not only the largest bomber in the world, it was also the the largest airplane ever built.

was based upon an Army Air Corps specification that had been issued back in 1935, six years before the United States entered World War II. Those six years were critical, because the state of the art for aviation technology advanced considerably during that period. As an operational bomber, the XB-19 was obsolete before it was even finished.

The only traces it left behind are two enormous 8 foot diameter wheels from its landing gear; one at the National Museum of the U.S. Air Force in Ohio and the other in the collection of the Hill Aerospace Museum in Utah.

https://www.historynet.com/the-douglas-xb-19-was-the-biggest-bomber-in-the-world-and-a-big-failure/

https://elpoderdelasgalaxias.wordpress.com/2025/01/06/douglas-xb-19-the-devil-is-in-the-details-xx/