The National Society of Conservative and Unionist Agents was set up as the professional body for Agents in November 1891. It reflected the trend for Party political business and especially electoral work to be carried out by a new class of skilled Agents instead of through local solicitors' firms, and a desire from Agents to consolidate their status as professional men. Shortly after this, it commenced publication of the monthly journal, The Tory (Shelfmarks: PUB 1/1-3), which continued until 1898. From 1902 it was followed by the Conservative Agents' Journal (Shelfmarks: PUB 2/1-13/20).

The National Society began as a federation of the existing regional unions of Conservative Agents. The move towards creating a national body began with the passing of a resolution in favour at a meeting of the Northern Association in Durham on 22nd February, 1890, a copy of which was then conveyed to the other regional Agents' bodies, followed by deputations to discuss the proposal. The Yorkshire, Midland, Eastern, and Western bodies agreed to join, but the North of England, Metropolitan, and Home Counties initially remained outside. Scottish and Welsh Agents agreed to join shortly after its formation.

The first formal meeting took place in Birmingham on 25th November, 1891, chaired by Mr Middleton, the Chief Agent. At this same meeting, the National Society drafted a Code of Rules for Agents, approved the form of certificates, and appointed a Board of Examiners.

In 1925 a Joint Examination Board was established and, with National Union approval, Agents appointed after 1933 were required to hold the Board's examination certificate. Central Office assisted with the training and examination of Agents, part of which was undertaken at Ashridge College and Swinton College.

The increasing employment of a full-time Woman Organiser specifically to deal with women's associations and branches led to the development of a parallel organisation, the National Society of Conservative & Unionist Women Organisers in the 1920s. Women did not finally become eligible to take the Agents' examination and join the National Society of Agents until 1946.

As a result of dwindling numbers following the Conservative Party's decision to stop training Agents and appoint in their stead 'Campaign Managers', the National Society changed its name to the National Society of Conservative Agents and other Campaign Staf' (NSCACS) at its Annual General Meeting in May 2012. The objects of the NSCACS are: