AlliedBarton

Allied Universal a security officer company based in the United States. It also offers security systems solutions, janitorial services and staffing. It is a combination of earlier companies - Barton Protective Services, Spectaguard, Initial and Allied Security. In 2016, the company merged with Universal Services of America and was named Allied Universal.

Allied Security, Inc. was founded in 1957 in Pittsburgh, Pennsylvania. The company provided contracted security guards and related services.

In 2000, Philadelphia, Pennsylvania-based, Spectaguard acquired Allied to form Allied Security and as a result became the fourth largest security company in the United States. Three years later, in 2003, Allied Security acquired Professional Security Bureau. Within a year, in 2004, Allied acquired Security Systems Inc. (SSI) of Malden, MA and Barton Protective Services to form AlliedBarton Security Services - creating the largest American-owned contract security services company in the United States. Two years later, in 2006, AlliedBarton acquired Initial Security for $73.6 million.

In 2015, Wendel, a Paris-based private-equity firm, acquired AlliedBarton Security Services for US$1.67 billion.

In 2016, AlliedBarton and Universal Services of America announced their intention to merge, pending regulatory commission approval. The merger was completed in August 2016, with the combined company being called Allied Universal. With this merger, Allied Universal is the largest security company in North America.