From the book Vision of Spiritual Order Blair(1998) describes Cornell's friendship with Duchamp:

"Cornell was also influenced by Duchamp, not just formally but conceptually to. Especially important here is the portable museum Duchamp constructed, the Boite en Valise (1936-41), which he originally made in order to carry reproductions of his work across the French border during the Nazi occupation of France. It had the appearance of a salesman's sample case, for Duchamp disguised himself as a cheese merchant for his journey. Once opened, it revealed a miniature world, with items packed, displayed and compartmentalised together. The Boite en Valise is technically immaculate, and the placing of things was fastidiously worked out. Later in the 1940's in America, Duchamp reproduced 200 copies of his portable museum. Cornell's interest in Duchamp's portable museum was such that he actually worked on it with Jacqueline Monnier in order to help produce the 200 copies". In working on Duchamp's Boite-en-Valise (see pic left) I think it is possible Cornell would have been attracted to the romantic history behind the piece. Either way he went on to create his own installation Romantic Museum in 1946 and returned to the 'museum in a box' theme in his box constructions again and again. In his early work Cornell used many formats for his surreal images and objects, including: glass bottles and jars, round and square cardboard boxes, cut-out books, and found cabinets, before settling on the simple rectangular wooden box. The history here is not straightforward because Cornell worked on many projects in parallel over many years, but I believe that once he began to concentrate on the 'box format', he had a much freer and poetic approach to his work. Waldman (2000) states that: "During the 40's, as Cornell's interest in the aneccdotal and the illustrative deminished, the object or image, its texture, colour and structure, gave new meaning to his work. Nowhere is this more evident than in the Medici series, which represents Cornell's coming of age".

I believe consolidating 'the box' format allowed Cornell to concentrate solely on the aesthetics of the contents. I also believe Cornell was an intuitive artist, he 'tinkered' with some of his boxes for many years creating layers within layers by adding or replacing objects, or trying out what he refered to as 'new variants, or variations on a theme. In doing this I believe Cornell discovered that he needed the simple rectangular format to restrain his highly imaginative works. In the simple box construction with its many diverse objects and images, we are left with works of art that trigger multiple ideas with myriad connections.

'The box' (part 4)
And finally, describing contemporary box ideas, the influence of Marcel Duchamp and why this is important in the story of how Cornell began to consolidate the 'box format'.