Yes, Gregory Corso wrote poetry while in prison. He was sentenced to 3 to 5 years in prison in 1951 for breaking and entering, and he was incarcerated in the New York State Penitentiary in Dannemora. While in prison, Corso wrote poems about his experience, including "The Drunken Monk" and "Carnival."
Musing with the Maverick: Discovering Gregory Corso’s Remarkable Literary Journey