There are many home security systems on the market today, and it’s no wonder, with crime rates being as high as they are. Most people think of companies like ADT when they think about using the highest forms of technology to protect their home or business. So, it may be surprising that ADT started in 1874.

ADT didn’t start out as a security company. In fact, ADT stands for American District Telegraph, and was a grouping of 57 different telegraph delivery groups. Unfortunately for the telegraph companies, the telephone became quite popular and really reduced how many telegraph deliveries there were. ADT tried to branch out into other businesses to supplement its waning telegraph business.

After a couple of decades of struggling financially, ADT sold its telegraph business to Western Union and the remaining portion of its business to AT&T. ADT then used its resources to create fire alarms and eventually, burglar alarms. Starting around 1910, burglar alarms became a major portion of ADT’s business. ADT continued along this vein until the 1960s, when it became a publicly traded company.

ADT faced a pretty major hurdle in 1964, when it was legally found to be a monopoly since it provided four out of five home security systems in existence at that time. The company had forced many competitors out of business by undercutting prices, and as a result, was forced to adopt a national price list.

After this major issue, and a series of investments from outside companies and groups (including a purchase from the United Kingdom’s Lord Ashcroft), ADT continued to grow. By 1995, ADT had more than one million customers, and was gaining the attention of other major companies. In 1997, Tyco purchased ADT from Lord Ashcroft, but did so using a “reverse takeover,” meaning that the company was allowed to keep Lord Ashcroft’s tax status in Bermuda.