Late 1800s	Telegraph dominates communications. The Late 1800s: In the late 1800s, the telegraph - as created by Samuel F.B. Morse and developed for commercial use by Alfred Vail - was king of communications. Messages were composed in a customer's office, written out and delivered by hand to a local district telegraph office. There, the messages were coded for swift transmission over telegraph lines to the receiving district's office, where they were decoded, transcribed and carried to their destinations by young boys. Many telegraph delivery companies came into existence during the late 1800s, and since each company served only its own particular district, they were appropriately known as "district" companies.
1874	American District Telegraph (ADT) is formed through the affiliation of 57 district telegraph delivery companies. In 1874, 57 diverse "district" telegraph delivery companies were joined to create the new American District Telegraph Company - the forerunner of today's ADT.
1880s	Call boxes (electric signal devices) allow interactive communication between customers and ADT. Messenger service is an important element in ADT's success.
1890s	Advanced Call Boxes and multi-signal electric protection systems move ADT to a position of prominence in security protection. Electric signal devices available in 50 towns. Messenger service accounts for 70% of ADT's revenues. With the advent of advanced Call Boxes and multi-signal electric protection system in the early 1890s, ADT became a pre-eminent security protection company. The multi-signal Call Boxes allowed watchmen at businesses to do more than just signal for police or fire department assistance - now he could also send a specific signal to the ADT office, at designated times, to let the monitoring office know that all was well. If a district office didn't receive its scheduled signal, something was assumed amiss, and help was dispatched. By 1899, electric signal services were still only available in 50 towns, though messenger services were widespread throughout more than 500 localities.

Early 1900s	Messengers are often doubling as watchmen, or "roundsmen." Their signal timers are monitored at ADT central offices. Signal-monitoring operations were by this time often run by employees recruited from the established messenger services. These messengers often also doubled as watchmen or "roundsmen," who both delivered messages and checked on property on a pre-ordained schedule.   In 1901, ADT was incorporated as a subsidiary of Western Union. Still, since each of ADT's 57 district companies had developed independently, the many offices of the security company operated at a variety of levels, with different systems, equipment, and operating practices. To begin to correct these incompatibilities, ADT separated its messenger services from the signal business. It was the signal operations that were to eventually become the ADT we know today.
1901	ADT becomes a subsidiary of Western Union. Signal service and messenger service separated.
1909	Western Union and ADT come under the control of AT&T. In 1909, Western Union (and ADT) came under the control of AT&T, whose company policies and organization changed the ADT organization. In 1910, AT&T President Theodore N. Vail took the reins at AT&T, and as a result, ADT concentrated fully on the signal business.

1910-1930	ADT makes advances in security technology.
War Years	ADT automates security systems. War years As more and more young men were called to the armed services, the resulting domestic manpower shortage drove the demand for new and better protection systems that would not only detect problems, but signal an alarm automatically. Because ADT provided a unique integration of systems and services, it was a logical step for the company to create these automatic services. As a result, the company pioneered developments such as the Teletherm automatic fire detections system, the Telewave automatic intrusion system, and other advancements.
Post war
1969	ADT becomes a publicly owned company with its stock listed on the NYSE. As ADT began to turn its attention toward an international market, in 1969 it became a publicly owned company with its stock listed on the New York Stock Exchange

Early 1970s	New, fast computer-driven technology including first solid-state device and installation of first large, two-way multiplex proprietary system. First automated Central Station - a direct forerunner of today's Customer Monitoring Center network. Newer, faster technology was the watchword of the seventies, which ushered in the company's first solid-state device and the installation of the first large, two-way multiplex proprietary systems. This was followed by the first ADT automated Central Station - a direct forerunner of today's highly sophisticated, integrated Customer Monitoring Centers network.
1974	ADT's 100th anniversary. Micro-computer based security systems now in use.  ADT celebrated its 100th anniversary, and by that time, powerful micro-computer-based security systems had replaced the old telegraphic Call Boxes
1981	Safewatch® residential system introduced. With the unveiling of the Unimode fire system in 1980, to the first CentraScan computer-based proprietary security system, through the introduction of the Safewatch® residential systems, the eighties were ADT's decade of leveraging its technological edge to the fullest corporate advantage. It was also during the eighties that ADT inaugurated central station monitoring, which would become the backbone of its future success.

1980s	ADT increases its technological lead.
Late 1980s	ADT changes its name from American District Telegraph Company to ADT.
1987	ADT purchased by the Hawley Group, Ltd., and renamed ADT Security Systems, Inc. U.S. headquarters relocated from NYC to Parsippany, NJ.
1988	Safewatch® Custom system launched.
Early 1990s	Wireless Safewatch® introduced. Focus® System introduced. Mid 1990s Company passes the one-million-customer milestone.   1998 ADT, Ltd. acquired by Tyco International Ltd.   2000 and beyond Today, and in the future, ADT remains committed to providing peace of mind and unsurpassed customer service in the protection of your home, your business, and the government.