In 1885, he joined the Social Democratic League, and the Rotterdam Cigar Makers' Union, becoming its secretary in 1887.
[1] Eichelsheim attended the 1896 Congress of the Socialist International, and although initially walking out in protest at its support for parliamentary activity, he was won around, and soon joined the Social Democratic Workers' Party (SDAP).
However, he was often out of work due to his activism, trying to find employment under a pseudonym, and eventually starting his own tobacco factory, with the support of the ANBT.
[1] Eichelsheim supported the formation of the Dutch Confederation of Trade Unions (NVV) in 1906, and that year also began working full-time for the ANBT.
[1] After World War I, he was involved in re-establishing the International Federation of Tobacco Workers, and was elected as its president.