The rapid industrialization of Curaçao, based on oil refining, resulted in an urgent need for labor which the small community could not provide sufficiently. The Portuguese, mostly from Madeira, were among the immigrant laborers who came by the thousands from the 1920s until the 1950s. A small group managed to stay either at the refinery or in the agricultural and grocery sector while others came to join them. This nucleus of permanent citizens evolved since the 1960s onwards till the Portuguese emerged as a very strong entrepreneurial group particularly in the supermarket branch, but also in some other market segments.