When an eccentric and reclusive hospital janitor died in 1973, his landlords were amazed to find hundreds of canvases and thousands of wildly imaginative illustrations stashed away in his lodgings.
Darger was a self-taught artist, and his visionary style and subject matter - predominantly featuring enslaved children escaping tyranny - was informed by a mixture of historical narrative, personal experience and American popular culture.
Today he is considered a leading protagonist of the Outside Art movement, a term used to describe art created outside the boundaries of the established art scene, mainly by patients of psychiatric hospitals and children.
The exhibition displays a collection of 45 Darger works recently acquired by the museum, as well as loans from international art institutions.
A 2004 film entitled In the Realms of the Unreal provides a fascinating insight into the artist's work and his sad, solitary and unusual life.