In 1901 an awkward young man introduced himself to Chicago radicals as Fred Nieman, German for Fred Nobody. They were so unnerved they assumed he was a government spy and shut him out, yet weeks later he would alter American history by firing two bullets into a sitting president at point-blank range.

This deep dive traces the chronological and psychological journey of Leon Czolgosz, an American factory worker who became a radicalized lone wolf, examined impartially as historical fact.

• His difficult immigrant childhood, his mother's early death, and grueling industrial labor from a young age.
• The economic panic of 1893, wage cuts, and his drift from a moderate workers' club toward anarchism.
• His isolation on an Ohio farm, obsessive reading, and rejection by radicals who publicly warned others about him.
• His ...