The Civil Service Association of Alberta (CSA), the precursor to the Alberta Union of Provincial Employees, was founded on March 19, 1919 as a reaction by Albertan civil servants to working conditions that had deteriorated during World War One.

The CSA was legally acknowledged by declaration of incorporation under the provincial Societies Act from 1919 to 1968. In 1968, the incorporation of the CSA came under the Civil Service Association of Alberta Act. Also in 1968, the Public Service Act (ch.81, Alberta Statutes) and the Crown Agencies Employee Relations Act (ch.17, Alberta Statutes) were enacted giving the CSA the sole right to negotiate on behalf of employees of the Government and on behalf of members who were employees of Crown Boards and Agencies. In 1972 both Acts were amended to include provisions for binding arbitration. On June 14, 1976 the Civil Service Association of Alberta Act was repealed and the successor organization, the Alberta Union of Provincial Employees, was incorporated under the Societies Act.

The CSA was governed by annual conferences at which each branch was entitled to representation and delegates decided the course of the union for the following year. The Provincial Executive was also elected at the annual conference and charged with the responsibility of carrying out the conference delegates' decisions. In addition to the Executive, various branch committees were elected to assist with administration, including committees on grievances, recreation, and education.

When the CSA was founded in 1919, the membership was approximately 450 and grew to over 24,000 members by 1976.