Anarchism
During the economic crash of 1893, the wire factory that he was working at began cutting wages which resulted in workers strikes. He would end up getting fired under his real name since he was participating in the strikes, but would later apply and get his job back applying as Fred Nieman. With the country currently experiencing economic instability and many other strikes, this event further exposed him to the dispairity between those rich and poor. Being unstatisfied and looking for aid, he would join the Knights of the Golden Eagle socialist club that promised working men aid. Clubs at the time had simple requirements such as having good moral character or being able to support ones self, so it's real plausible that anyone could get in. With the club not meeting all of his needs, he would eventually go on to join a lesser known, more radical socialist group called the "Sila" ("Force" in Polish) Club before it would disband after a short amount of time.1
In 1898 he would leave his job due to what some claim to be a nervous breakdown, but, his father only notes health issues. He would move back in with his father and stepmother, which he was not a fan of, back on their farm near Cleveland, Ohio. He would keep try himself there, do occasional work to get by, but was always butting heads with the stepmother. This all so far, doesn't seem too bad and point toward him being crazy, but his parents would later comment about his time there and him in general. They said to the press that "he (Leon) was taciturn (quiet), would never speak to anybody and would often mumble in an uninteligible manner"2 said his father. His stepmother would be straight forward and state that "He is insane... I have always said he was crazy" and in the same comment would question why "he should want to take the Presidents life, he didn't seem to take much interest in politics" and even that she believed "he voted for McKinley."3 Showing some clear confusion with his actions.
Eventually, one day he would attend a lecture held by prominent anarchist Emma Goldman. He found the ideas in the speech to be of great value and this would end up getting him in interested in the Anarchist movement. When the lecture ended, he would go up to the platform to ask where get more info on the ideas. This would lead him to continue researching the ideas of the movement, continually visiting members of the movement to ask questions that began to alarm them. This would lead to him meeting the writer of the "Free Society" newspaper to ask questions that worried him so much that he sent out a warning about him in the newspaper. A section of the warning read "The attention to the comrades is called to another spy...(he is) pretending to be greatly interested in the cause (anarchist movement), asking for names or soliciting aid for acts of contemplated violence" further going on to warn readers if anyone sees him.4
It is clear at this point, that Something had changed with Leon, he was no longer the quiet guy that kept to himself.
Footnotes
1.St. Louis Post-Dispatch. “LIFE OF CZOLGOSZ THE ANARCHIST WHO SHOT PRESIDENT,” 8 Sept, 1901, Sunday Morning edition, v54n18 page 4 (col. 3 parapgraph 1).
https://www.newspapers.com/image/138260734/
2. St. Louis Post-Dispatch. (col. 1 parapgraph 3).
3. St. Louis Post-Dispatch. (col. 1 parapgraph 4).
4. Everett, Marshall. n.d. "Complete Life of William McKinley and Story of His Assassination" 1901: pp. 87 https://archive.org/details/completelifewil01evergoog/page/n95/mode/2up