ABM Industries Inc. is a facility management provider in the United States founded in 1909 by Morris Rosenberg in San Francisco, California.

[6] In 1909, Morris Rosenberg, the company's founder, began cleaning shopkeepers' windows in San Francisco, CA.

[8][9] Ted purchased an electrical company in that same year and ABM cleaned Navy ships and installed wiring on Water Buffalo amphibious vehicles during World War II.

[8] ABM's growth continued throughout the post-war years and the company went public in 1962 in the over-the-counter market[10] with Ted serving as chairman and Sydney as CEO.

[16] Among those killed was Roko Camaj who was on the 105th floor of the South Tower when it was struck by United Airlines Flight 175.

[17] A window washer that was working for ABM managed to use his squeegee to open an elevator door, saving six people.

[19] Also in 2007, ABM completed the acquisition of OneSource Services Inc. (London AIM: OSS) for $365 million in cash.

[buzzword] The company also centralized key business functional support areas (finance, HR, marketing, legal, etc.)

[38] In September 2017, ABM Industries purchased GCA Services Group for $1.25 billion,[27] the largest acquisition in the company's history.