LeWitt wrote a letter to the sculptor Eva Hesse in 1965 when she was paralysed by self-doubt. He told her to try to do some bad work. The worst you can think of and see what happens but mainly relax and let everything go to hell. Two days after Hesse's death in 1970, he created Wall Drawing 46 in her memory, using non-straight lines for the first time. The aesthetic shift was credited to her influence.

He was born in Hartford, Connecticut, in 1928, to Russian Jewish immigrant parents. His father died when he was six. He drew on wrapping paper from his aunt's shop and took art classes at the Wadsworth Atheneum. He served in the Korean War, then settled in New York.

From 1968, he created over a thousand numbered wall drawings. He conceived them as musical scores that anyone could execute: a set of written instructions, carried out by other people, with the physical drawing destroyed after each exhibition. The idea, he argued, was the machine that makes the art. The execution was secondary. He championed and financially supported women artists who were being sidelined by the male-dominated art world. He refused to participate in celebrity culture and remained deliberately private. He died in 2007.