In 1897 Dansk Arbejdsmandsforbund, DAF, was established by unskilled workers and constitutes the beginning of the 3F we know today. In 1959 DAF changed its name to "Arbejdsmands- og Specialarbejderforbundet" and in 1974 to "Specialarbejderforbundet i Danmark" (SiD).
When workers in the end of the 1890s claimed their right to organise, it led to a major conflict between the workers and the employers. As a settlement, "Septemberforliget" was negotiated, which lays out the structures of the Danish Labour market we know today.
Women had no access to the union - male workers feared that women would put pressure on the wages if they joined the unions and could participate in the male-dominated areas of work. But the women workers fought for their rights and established their own unions. In 1901 they established a federation for women's workers; "Kvindeligt Arbejderforbund" (KAD).
As still more women entered the labour market and were also employed in some male-dominated work-areas, it proved still more difficult to keep excluding women from the unions. In 1971, SID therefore allowed women to gain membership. KAD, on the other hand, never allowed men to join the women’s union. Members of SID were both unskilled and skilled workers but focused on the conditions of the working class and the most marginalized in the labour market. Both KAD and SID became known for their political views on gender equality and social justice.
During the 1990’s KAD and SID approached each other and in 2004 this led to a merger. SID brought almost 313,000 members and KAD about 74,000 members to the new federation; Fagligt Fælles Forbund (3F) or United Federation of Workers in Denmark. The federation gained more and more members during the 2000s as more trade unions joined and reached the highest level in 2006 with 367.000 members. Today, the membership rates are declining but 3F is still the largest trade union federation in Denmark with approximately 273,000 members.