His story is far too long to tell in full detail here, but very briefly: he was born in the 1890s, and and put in a catholic boy's home in 1900 when his father could no longer care for him. There, he was diagnosed by a doctor as "feeble" who said "Little Henry's heart is not in the right place".
When he was 16 he escaped the home, and walked from Lincoln back to Chicago, witnessing a tornado on the way - he walked over 100 miles. In Chicago he found work as a janitor in a hospital, and worked there until his retirement more than fifty years later, retiring only when forced by his employers.
He was intensely reclusive, and it was only after he passed away in 1973 that his landlords discovered his prolific work.
He had, over his lifetime, written the longest work of fiction on record - In the Realms of the Unreal (15,145 pages) - about the seven Vivian sisters - accompanied by three volumes containing several hundred illustrations. He had also written an autobiography of over 5,000 pages, a daily journal chronicling the daily weather for ten years, and a second work of fiction of over 10,000 pages. He is now one of the most recognised 'outsider artists', thanks to the efforts of his landlords.
The 2004 Documentary In the Realms of the Unreal brings his work to life beautifully (and is, strangely, narrated by Dakota Fanning)
I'd love to know what other people think of Darger's work...