Leupin used a monumental linked chain to symbolize Swiss unity for a national trade fair poster during World War II. He wrote:
The chain seemed to me the most forceful and at the same time the most suggestive theme for a poster…I wanted to illustrate the dependence upon each other of the different branches of the economy, of the cantons and, last but not least, of the four parts of the country, and therefore I originally marked the four links of the chain with the symbols of commerce, industry, crafts and science. In the course of my work I realized, however, that the greatest simplicity achieved the most powerful effect. So I eliminated all the details, the emphasis thus lies more clearly upon cooperation.
This poster is in MoMA's permanent collection.