With the Great Depression, Johnson became politicized and turned leftward, joining the radical Book and Magazine Writers Union.

In 1942, he developed the Barnaby strip which would make him famous for the left-wing daily newspaper PM.

Johnson created his series of more than 100 mathematical paintings inspired by geometric principles and mathematicians.

The paintings were inspired by famous mathematicians such as Galileo, Euclid, Descartes, and many more, and the titles of said paintings are references to each mathematician--"Proof of the Pythagorean Theorem" for Euclid, "Pendulum Momentum" for Galileo, and "Square Root of Two" after Descartes.

[10] Johnson made an effort to differentiate his paintings from contemporary art in that his are based on the mathematics of geometry, not solely the shapes.

Additional books were supposed to appear, but publication was suspended upon the death of Judy Lynn Del Rey.

The five-volume collection, featuring all ten years of Barnaby, is expected to be complete in 2019.