ADT Corporation was founded in 1874 and today is one of America’s leading alarm and security monitoring companies. Based in Boca Ranton, Florida, the company operates in 35 countries around the world, supplying alarms, monitoring equipment and peace of mind to homes and small businesses. In South Africa, ADT provides armed response teams and around-the-clock surveillance. Originally known as American District Telegraph, ADT started out as a telegraph delivery business. Then from 1910, under new leadership from AT&T, it started to switch focus to other fields such as fire and intruder alarms. In 2011 ADT boasted an estimated 6.4 million clients and yearly turnover of $3.1 billion. And in 2012 it split from Swiss parent company Tyco International and commenced trading on the New York Stock Exchange as an independent company.