As Jackson's disciplinary infractions grew he spent more time in solitary confinement, where he studied political economy and radical theory. He also wrote many letters to friends and supporters which would later be edited and compiled into the books "Soledad Brother" and "Blood in My Eye", bestsellers that brought him a great deal of attention from leftist organizers and intellectuals in the U.S. and Western Europe. He amassed a following of inmates, including some whites and Hispanics, but most enthusiastically with other black inmates.