[7] Kelly moved to England in 1898, partly to meet his father's relatives, but also to engage with London's renowned circle of anarchist revolutionaries, a prospect which he had looked forward to with impatience.

[2][7] It was there, among newfound friends and comrades, anarchist thinkers and propagandists, that Kelly spent his happiest days, and in the words of Havel "fortified his ideal with historical, economical and social facts and data".

[2] In England, he worked alongside prominent anarchist intellectual Peter Kropotkin, with whom he formed a close friendship, visiting the Russian often at his home in Bromley, Kent and finding him to be an enthusiastic comrade and great teacher.

[2] Though he became increasingly less active in the labor movement whilst in England, he collaborated on the prominent London anarchist newspaper Freedom, alongside Kropotkin, Tcherkesow, Louise Michel, Max Nettlau and John Turner until his return to the United States in 1904.

[1] Kelly struggled financially in the Great Depression, writing in 1932 that he had failed to earn enough in the preceding year to support himself, and being refused a TVA position after listing his political affiliation as "anarchist".

Kelly sought to establish an anarchist society founded on voluntary association, in which coercion and authority would be replaced with personal freedom, individual autonomy and mutual aid.