The following is a short history of the Association and how it helped form the present SEIU Local 790.

The Municipal Civil Service Employees Association formed in San Francisco on July 26, 1902. The records of this organization burned in the Fire of April 18, 1906. In March 1914 the association was reorganized as the San Francisco Municipal Civil Service Association. This group would later affiliate with the Federation of Municipal Employees and the California Federation of Civil Service Associations. In 1945 the organization was again renamed: the Civil Service Association of San Francisco. It was incorporated April 16, 1948. The Association consistently fought for improved health care for city workers, and pushed the City into accepting salary standardization surveys to bring municipal employee wages to competitive levels.

In early December 1945 the San Francisco Labor Council, the San Francisco Building and Construction Trades Council, and the Bay Cities Metal Trades Council adopted a resolution approving the formation of an AFL Departmental Council of San Francisco city employees. Fred Lorenzetti and Joseph Moreno were named president and vice president, respectively, and Dan Scannell became secretary-treasurer as well as business agent. Meetings were to be held on the second and fourth Monday of the month. On March 29, 1946 the San Francisco Labor Clarion reported the Minutes of the first meeting of the new "AFL Council of San Francisco City Employees," affiliated with the American Federation of State, County and Municipal Employees (AFSCME). San Francisco City and County Employees, AFSCME Local 747 was the precursor to this AFL Council.

A year later, there were references to a San Francisco City and County Employees Union Local 503, of the United Public Workers of America, CIO (otherwise known as State, County and Municipal Workers of America, CIO). Local 503 was referred to as Local 503/400 in 1950, probably reflecting a change in affiliation from CIO to AFL. At this time, John Jeffrey was their business representative. He seems to have been involved with this union for quite some time. In 1950 Local 503/400 also affiliated with the California Council of the BSEIU.

Local 400 merged with the Civil Service Association of San Francisco in 1972. In February 1982, United Public Employees Local 400 voted to merge with UPE Local 390 (East Bay). Joint by-laws were approved for the new SEIU United Public Employees Local 790 in February of 1985.