1876: Alexander Graham Bell invents the telephone, for which he receives two patents. With two financial backers founds the company that becomes AT&T.

1877: The Bell Telephone Company, the first predecessor company to AT&T, is formed and issues stock to the seven original shareowners.

1878: The first telephone exchange in the United States opens in New Haven, CT under license from Bell Telephone. Within a few years, licensed telephone exchanges open in every major city in the country. These franchises, together with the parent company, eventually become known as the Bell System.

1882: The American Bell Telephone Company acquires a majority interest in the Western Electric Company, securing a supplier for telephone equipment.

1885: The American Telephone and Telegraph Company is formed as a subsidiary of then-parent American Bell Telephone Company, with a charter to build and operate the original long distance network. By the end of the year, AT&T completes its first line, between New York and Philadelphia. The initial capacity of the line was one call.

1892: AT&T reaches its initial goal, opening a long distance line connecting New York and Chicago. The circuit could handle only one call at a time. The price was $9 for the first five minutes.

1894: Alexander Graham Bell's second telephone patent expires, opening the telephone industry to competition. Within a decade, over 6,000 companies went into the telephone business in localities across the country.

1899: Michael Pupin of Columbia University and George Campbell of AT&T independently develop the theory of loading coils. With loading coils, which reduce the rate at which a traveling telephone signal weakens, it becomes possible to build longer telephone lines.

1899: In a corporate reorganization, American Telephone and Telegraph acquires the assets of its parent, American Bell Telephone, and becomes the parent of the Bell System.

1907: Theodore Vail begins his second term as President of AT&T (he had been president in 1885-1887) He develops the philosophy, strategy, and structure that guides AT&T and the Bell System for the next seventy years.

1908: Vail begins national advertising, and introduces the slogan "One System, One Policy, Universal Service."

1913: AT&T settles its first federal anti-trust suit with a document known as the Kingsbury Commitment. It establishes AT&T as a government sanctioned monopoly. In return, AT&T agrees to divest the controlling interest it had acquired in the Western Union telegraph company, and to allow non-competing independent telephone companies to interconnect with the AT&T long distance network.

1915: Using the first practical electrical amplifiers, developed by AT&T's Harold Arnold, AT&T opens the first transcontinental telephone line. The new line connects the network that AT&T had been building out in every direction from New York since 1885 with a separate network that had been constructed by AT&T's Pacific Telephone subsidiary on the West Coast. In effect, it connects telephones throughout the continental United States. The ceremonial first call on Jan. 25 has four locations: New York City, San Francisco, the White House in Washington, D.C., and Jekyll Island, Ga., where AT&T President Theodore Vail is at the time. Service is available to all telephone customers, but at an initial price of $20.70 for the first three minutes between New York and San Francisco, volume is low.

1919: AT&T installs the first dial telephones in the Bell System, in Norfolk VA. The last manual telephones in the system were not converted to dial until 1978.

1922: AT&T opens WEAF, the first commercial radio station in New York. AT&T left radio broadcasting in 1926, retaining the networking facilities used to send programs to stations across the country.

1925: AT&T establishes Bell Telephone Laboratories Inc. as its research and development subsidiary.

1927: AT&T begins transatlantic telephone service, initially between the US and London. The conversations crossed the Atlantic via radio. The initial capacity is 1 call at a time, at a cost of $75 for the first three minutes.

1927: AT&T presents the first demonstration of television in the United States. Secretary of Commerce Herbert Hoover's live moving image was transmitted over cable to New York, where it was seen by AT&T President Walter Gifford, and a large audience.

1934: AT&T inaugurates transpacific telephone service, initially between the US and Japan. Calls travel across the Pacific via radio. The initial capacity is one call at a time at a cost of $39 for the first three minutes.

1937: Clinton Davisson of Bell Telephone Laboratories wins the Nobel Prize in Physics for experimental confirmation of the wave nature of the electron. He becomes the first of seven Nobel Prize winners produced by AT&T.

1941: The first non-experimental installation of coaxial cable in the network is placed in service between Minneapolis, Minn., and Stevens Point, Wis. The type of coaxial cable installed was invented at AT&T in 1929 and is the first broadband transmission medium.

1946: AT&T begins offering mobile telephone service. With a single antenna serving a region, no more than 12 to 20 simultaneous calls could be made in an entire metropolitan area.

1947: AT&T develops the concept of cellular telephony. The technology to realize the concept did not yet exist.

1947: AT&T Bell Telephone Laboratories scientists John Bardeen, Walter Brattain, and William Shockley invent the transistor, the first solid state amplifier or switch, and lay the foundation for modern electronics. The three shared the Nobel Prize in Physics in 1956 for the achievement.

1948: AT&T begins offering networking services for television on facilities connecting major cities in the northeast and midwest. The service reaches the west coast in 1951. Television networks use this service to transmit programming to their affiliated stations around the country.

1951: AT&T introduces customer-dialing of long distance calls, initially in Englewood, NJ. The national rollout takes place over the second half of the 1950s. Until this innovation, all long distance calls required operator assistance.

1956: AT&T and the US Justice department agree on a consent decree to end an antitrust suit brought against AT&T in 1949. AT&T restricts its activities to those related to running the national telephone system, and special projects for the federal government.

1956: AT&T opens for service TAT-1, the first trans-Atlantic telephone cable. The initial capacity is 36 calls at a time at a price per call of $12 for the first three minutes. Since trans-Atlantic service opened in 1927, calls had traveled across the ocean via radio waves. But cables provide much higher signal quality, avoid atmospheric interference and offer greater capacity and security.

1958: AT&T introduces the first commercial modem.

1962: AT&T launches Telstar I, the first active communications satellite. Telstar transmits the first live television across the Atlantic.

1963: AT&T introduces touchtone service, with a keypad replacing the familiar telephone dial, initially in Greensburg and Carnegie, Pennsylvania.

1964: AT&T opens TPC-1, the first submarine telephone cable across the Pacific. It went from Japan to Hawaii, where it connected to two cables linking Hawaii with the mainland. This brought the same improvements to trans-Pacific service that TAT-1 had brought to trans-Atlantic service in 1956.

1965: AT&T installs the world's first electronic telephone switch (special purpose computer) in a local telephone exchange, Succasunna, NJ.

1968: AT&T introduces 911 as a nationwide emergency number.

1970: AT&T introduces customer dialing of international long distance calls, initially between Manhattan and London.

1971: Researchers at Bell Telephone Laboratories create the Unix computer operating system, which is designed to be hardware independent. It eventually becomes the underlying language of the Internet.

1975-1976: Computerization of the network begins as AT&T installs the world's first digital electronic toll switch, the 4ESS®, in Chicago. This switch could handle a much higher volume of calls (initially 350,000 per hour) with greater flexibility and speed than the electromechanical switch it replaced.

1977: AT&T opens its first Network Operations Center in Bedminster, New Jersey. With this center AT&T achieves real-time active management of its entire long distance network from a single location.

1977: In Chicago, AT&T installs the first fiber optic cable in a commercial communications system.

1982: AT&T and the Justice Department agree on tentative terms for settlement of anti-trust suit filed against AT&T in 1974. AT&T agrees to divest itself of its local telephone operations. In return, the Justice department agrees to lift the restrictions on AT&T activities contained in the 1956 Consent Decree. The agreement, once accepted by the court, becomes known as the Modification of Final Judgement or MFJ.

1983: In conjunction with the soon-to-be-divested Ameritech, AT&T opens the first commercial cellular telephone system in the United States in Chicago. The cellular franchises pass to the divested local companies in January.

1984: On January 1 the Bell System ceases to exist. In its place are seven Regional Bell Operating Companies and a new AT&T that retains its long distance telephone, manufacturing, and research and development operations.

1984: Equal Access carrier selection begins, first in Charleston WV. The Federal Communications Commission had mandated that all telephone subscribers choose which long distance company they would reach on dialing 1+ the number. This would level the playing field and bring full competition to the long distance telephone market.

1984: AT&T reduces long distance rates by 6.4 percent, as non-traffic sensitive costs begin moving from rates to local-company administered access charges. This was the first in a series of rate reductions over the next six years that totaled approximately forty percent.

1988: AT&T lays and opens TAT-8, the first fiber optic submarine telephone cable across the Atlantic. It has a capacity equivalent to 40,000 calls, ten times that of the last copper cable. (Today's cables have capacities equivalent to over 1,000,000 calls).

1991: AT&T acquires computer maker NCR Corporation in an attempt to realize the synergies it believed inherent in the coming integration of computing and communications.

1993: AT&T announces a definitive merger agreement with McCaw Cellular Communications Inc, the largest provider of cellular service in the United States. The acquisition is later renamed AT&T Wireless. AT&T completes the transaction in 1994.

1995: On September 20, AT&T announces that it is restructuring into three separate companies: a services company, retaining the AT&T name; a products and systems company (later named Lucent Technologies) and a computer company (which reassumed the NCR name). Lucent is spun off in October 1996, and NCR in December, 1996.

1999: AT&T announces general availability of its local residential telephone service in New York with a bundled plan called "AT&T Local One Rate New York." This is AT&T's first general reentry into the consumer local telephone business since the break up of the Bell System. It occurs under the provisions of the Telecommunications Act of 1966.

1999: AT&T acquires TCI, the second largest cable company in the United States. TCI becomes AT&T Broadband. The following year, AT&T Broadband acquires cable company MediaOne, and becomes the largest cable company in the United States.

2000: AT&T announces that it will reorganize into a family of companies – AT&T (including AT&T Business and AT&T Consumer), AT&T Wireless and AT&T Broadband. AT&T Wireless is spun off in July 2001, and AT&T Broadband completes a merger with the Comcast Corporation in November 2002.

2000: For the first time, the volume of data traffic on the AT&T network exceeds the volume of voice traffic.

2002: AT&T deploys a new nationwide intelligent optical network which restores service faster in the event of a failure or disaster. This new network also provides the capability to dramatically shorten provisioning time for new high-speed circuits for business customers who have direct access to the network.