rural South, Limburg and North Brabant, the party has a marginal position. In the Protestant and rural North, especially Groningen and Friesland, the party also performed well. Electorate In the period 1897-1919, when voting rights were restricted the party mainly received support from educated workers and young members of the Intelligentsia (lawyers, teacher, vicars and engineers). The SDAP was mainly supported by atheists and latitudinarian protestants. When universal suffrage was granted in 1919 the SDAP began to expand to all layers of the population, drawing heavy support from the working class. The party historically received strong support from the major cities, such as Amsterdam and Rotterdam, and the northern provinces of Groningen, Friesland and Drenthe and the industrial region Twente. Organisation Organisational structure The highest organ of the SDAP was the Congress, formed by delegates from the municipal branches. It convened once every year. It appointed the party board, decided the order of candidates on electoral lists for the Senate and House of Representatives and had the final say over the party program. Membership When the SDAP was founded in 1897 it has around 600 members organised in 25 municipal branches. In 1919 the party had around 49,000 members in around 645 municipal branches. In 1938 the party had around 88,000 members in around 650 municipal branches. The party's membership throughout its existence is displayed in the chart below. International organisations Between 1894 and 1914 the SDAP was member of the Second International, after World War I, it lost its international contacts. The party was a member of the Labour and Socialist International between 1923 and 1940. Pillarised organisations The SDAP had strong links with other socialist organisations in the socialist pillar. It had strong links with the largest trade union NVV. Two important means of propaganda of the party were the social democratic broadcasting organisation VARA and the paper Het Vrije Volk. The youth organisation Arbeiders Jeugdcentrale (Workers' Youth Central, AJC) was a large youth organisation aligned with the SDAP, founded in 1918, with around 11,500 members in 1935. The women's association aligned with the SDAP was Samen Sterk (Together Strong) founded in 1912. The student's association aligned with the SDAP was the Social Democratic Students Club, (Sociaal-Democratische Studentenclub, SDSC). A Workers' Education Institute (Instituut voor Arbeiders Ontwikkeling IvAO) was set up in 1924 and a scientific bureau in 1935. But the SDAP also had close links with workers'