[1] There he became acquainted with socialist thinking and in 1884, joined the cause full-time, becoming a member of the American Group faction of the International Working People's Association, and later being appointed its treasurer.

[2] On May 4, 1886, Fielden was working delivering stone to German Waldheim Cemetery and had not heard of the planned demonstration at Haymarket for that night.

He had promised to speak to some workers, but upon returning home, he learned of an urgent meeting of the American Group at the office of the Arbeiter-Zeitung, a German-language anarchist newspaper.

[3] A short time later, there was a request from the Haymarket for additional speakers and Fielden, along with Albert Parsons, agreed to go and speak.

A Pinkerton detective reported that Fielden had, in the past, advocated the use of dynamite and the shooting of police officers.

He spent six years in prison until he was finally pardoned, along with co-defendants Michael Schwab and Oscar Neebe, by governor John Peter Altgeld on June 26, 1893.

After being released, he purchased a ranch along Indian Creek in the La Veta valley of Colorado, where he made his home with his wife and children.