AlliedBarton Security Services, headquartered in King of Prussia, is the largest American-owned and managed security services firm in the United States. Since 1957, AlliedBarton has been providing quality security services and highly trained personnel to clients in a number of industry sectors, including commercial real estate, higher education, healthcare, government, residential communities, manufacturing and distribution, financial institutions, shopping centers and other commercial facilities. Its approximately 47,000 employees and more than 100 offices nationwide service a client base of 3,700 + customers, which includes over 175 Fortune 500 companies across the country. Selected as Training magazine's "Top 100" in 2006, AlliedBarton's award-winning programs, on-the-job and web-based training focuses on preparing employees in a variety of security-related topics.