Sketch for a Large Picture in Progress, Representing Allegorically the Great Industrial Meeting of all Nations, 1851, 1851. This painting is an allegory of the first World¡¦s Fair - officially named the Great Exhibition of the Works of Industry of All Nations, but popularly referred to as the Great Exhibition of 1851. Six million visitors attended this event held in London, and its success inspired other countries to host their own versions of these international gatherings. William T. Walters and his son Henry frequently added to their collections at these fairs.