He also exhibited works in conjunction with the group Das Junge Rheinland, whose members included Otto Dix and Max Ernst.
He created free-standing and architectural sculptures for buildings designed by the architects Edmund Körner, Georg Metzendorf and Alfred Fischer.
In 1931, on the express recommendation of Max Liebermann, he received a scholarship from the Prussian Academy of Arts to study in Rome, and spent nine months at the Villa Massimo, working alongside the artists Werner Gilles, Ernst Wilhelm Nay and Hermann Blumenthal.
In the early summer of 1933 he was forced to emigrate via the Netherlands to Paris, his Jewish wife Hette and their two sons Till and Ule following on.
Despite Lammert's greatest endeavours to find work as a sculptor, efforts which led him all the way to Siberia, there were few opportunities in the Soviet Union for him to practise his art.
He worked in various architect's offices and ran drawing groups together with another exiled artist, the painter Heinrich Vogeler.
His wife used the money to set up the Will Lammert Prize, which was awarded by the German Academy of the Arts to numerous young sculptors between the years of 1962 to 1992.
After the First World War he was represented by the gallery owner Alfred Flechtheim, and participated in various exhibitions held by the group Das Junge Rheinland.
At the same time he was taking public commissions, including for example Mutter Erde (Mother Earth) in 1926, for the entrance to the South-West Cemetery in Essen, and a memorial to the war dead in Marburg in the form of a lion (1926/27).
After 1933, Lammert's early work was destroyed almost in its entirety in the run-up to the "Degenerate Art" campaign, on the instigation of its protagonist, Klaus Graf von Baudissin.
A bust of Karl Marx, which was on display in the entrance to Berlin's Humboldt University, was removed at the time of German reunification.