The SDAP was founded by members of the Social Democratic League (SDB) after a conflict between anarchist and reformist factions.

When the anarchist elements began to take full control of the SDB, important regional social democratic figures joined the group around Troelstra.

The twelve apostles nearly all came from the provinces of Friesland and Groningen or from large cities like Amsterdam and Rotterdam, and most were intellectual-type men like teacher, vicar or lawyer.

Both parties believed in an imminent revolution which would make an end to suffering and inequality between classes and between men and women.

In parliament the SDAP supported the social legislation of the Liberal majority cabinet, led by Nicolaas Pierson.

The confessional, Christian-democrat cabinet, composed of the Protestant Anti-Revolutionary Party and the Catholic General League ignored the Socialists.

But in reaction to the government legislation, moderate party members, including Troelstra, turned against the strikes.

The Dutch Confederation of Trade Unions (Nederlandsch Verbond van Vakvereenigingen, NVV) was founded in 1905 by Henri Polak.

Troelstra openly attacked the orthodox Marxists and the party congress in a formal resolution declared to oppose all labelling opportunists and revisionists.

In 1907, a group of orthodox Marxists around David Wijnkoop founded the magazine De Tribune, which attacked the revisionist leadership of the SDAP.

In the knowledge that they could not accomplish anything in parliament, the SDAP focused on the extra-parliamentary movement for universal suffrage, for both men and women, regardless of class.

The demonstration led to considerable controversy, when Queen Wilhelmina decided not to attend the Prinsjesdag ceremonies.

Samen Sterk tried to found labour unions for female employees, starting with house maids.

The SDAP, even the reformist Troelstra, refused government participation, because the party acknowledged one of its major ideals, national disarmament, could not be realised.

The cabinet intended to realise socialist demands, like universal suffrage, the state pension and the eight-hour working day.

During the war, the allies blockaded the Dutch ports, which in turn led to enormous lack of food: riots broke out in the major cities.

In a speech in parliament he demanded the resignation of the government, because he expected the army and the police to support the revolution.

The party began to shift their focus away from the revolution and towards the direct improvement of the position of the working class.

After 1936, however, it changed its course, giving into socialist demands by devaluating the guilder and allowing the national debt to rise in order to increase employment.

This course of moderation was suddenly interrupted by the incidents surrounding the mutiny on the cruiser De Zeven Provinciën.

In 1939, at the dawn of World War II, prominent SDAP members were asked to participate in a national coalition, led by Protestant politician De Geer; the dawning war was the extreme necessity that allowed the SDAP to enter government.

The SDAP first supplied two ministers (Albeda and Jan van de Tempel) and in 1944 they were joined by Jaap Burger.

They were joined by individuals from the Protestant Christian Historical Union (CHU) and Anti-Revolutionary Party (ARP) and members of the Catholic resistance movement Christofor.

Several famous SDAP-politicians, like Willem Drees had first built up a reputation in municipal government through initiating employment and housing programs.

In the Catholic and predominantly rural South, Limburg and North Brabant, the party has a marginal position.

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).

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.

Two important means of propaganda of the party were the social democratic broadcasting organisation VARA and the paper Het Vrije Volk.

A Workers' Education Institute (Instituut voor Arbeiders Ontwikkeling IvAO) was set up in 1924 and a scientific bureau in 1935.