Union activities became legal in Brazil based on the Law no.979, of January 6th, 1903, in the rural area, and on Decree 1.637 of January 5th, 1907, in the urban sector.

In their origins, urban unions did not correspond the needs which aroused from fights of the new workforce. It was before the reaction of the new urban bourgeoisie against rural landowners, and presented itself more as a political-intellectual movement than as a result of labor fights. We may say that in Brazil, up until the 30's, there was no such a thing as a deep union labor request involved in the search for advantages or rights conquest. The government of the 30's revolution did not take long to raise the issue of labor forces, which was still incipient. In 1934, classicist regimen and union plurality began.

In 1939, the Executive Law no. 402 of July 5th established the union's unity and the process of recognition by the Labor, Industry and Commerce Ministry, which were essential conditions for the unions to legally exist and represent their members.
In 1943, the Consolidation of Labor Laws took place, it was approved by the Decree no. 5.452.