He joined the Cigar Makers' International Union (CMIU), organizing local 100 in Philadelphia.
He was also active in the Philadelphia Central Labor Union, serving as its financial secretary in the mid-1880s.
[1] In 1885, Kirchner became the fourth vice-president of the CMIU, and its full-time organizer for Pennsylvania.
[1] Politically, he was considered to have anarchist sympathies, something which proved controversial with some other labor unionists.
However, in 1886, William H. Foster, secretary of the Federation of Organized Trades and Labor Unions (FOTLU), died, and Kirchner was appointed to complete his term.