The widest painting in the world would have to be Panorama of the Mississippi, John Banvard’s minutely detailed mural depicting scenes from 1,200 miles of the shore along the Mississippi River.
Although billed as being “3 miles long!” it was painted on a 1,200-foot-long canvas and was the result of a year-long journey Banvard took by raft and boat, sketchbook in hand.
The painting was a huge commercial success, Banvard displayed it to ticket-buyers around the world.
Unfortunately, after his death in 1891 it was cut up and the canvas used as theatrical backdrops.
There is no evidence that any of it has survived to the present.