In Stuttgart on January 22, 1889 Friedrich Wilhelm (called Willi) Baumeister became the family's third child, born after Klara and Hans. Their father Wilhelm Baumeister (1847-1931) was court master chimney-sweep. He had studied mechanical engineering at the Stuttgart Polytechnic, but early on had to take over his father's company, then in the third generation. Willi's mother Anna, neé Schuler (1861-1945), was the daughter of the decorative painter Friedrich Wilhelm Schuler.

On April 1, 1928 Willi Baumeister pursued his call to the Municipal School of Applied Arts (Städelschule) in Frankfurt. He was initially hired as a lecturer for the field of commercial graphics, typography, and fabric printing. He certainly would have welcomed taking on the painting class as well. This, however, was taught by Max Beckmann. In November Baumeister was awarded the title of professor. In the same month - with the arrival of his wife Margarete in Frankfurt - Baumeister began making regular diary entries, which he continued to do until his death.

For Baumeister - as for many artists - the 'Stunde Null' (zero hour) was a longed-for new beginning. His productivity had not suffered a real break during the years between 1933 and 1945, but now art production could take place in public again.