| 1847, | March 3—Birth of Alexander Graham Bell at Edinburgh, Scotland. |
| 1854, | January 18—Birth of Thomas A. Watson at Salem, Mass. |
| 1870, | August 1—Bell moves to America with his parents, arriving in Canada on this date, and settling at Brantford, Ontario. |
| 1872, | October 1—Permanent residence in the United States taken up by Bell at 35 West Newton Street, Boston. |
| 1875, | February 27—Written agreement between Bell, Sanders, and Hubbard forming “Bell Patent Association” to promote inventor’s work in telegraph field. |
| | June 2—Bell completes the invention of the Telephone, electrically transmitting overtones for the first time and verifying his principle of the electrical transmission of speech at 109 Court Street, Boston. |
| | June 3—First telephone instrument constructed by Watson according to Bell’s specifications. |
| | September—Bell at Brantford begins writing specifications for a telephone patent. |
| 1876, | February 14—Application for telephone patent filed with U. S. Patent Office, Washington, D. C. |
| | March 7—U. S. Patent 174,465 issued to Bell, covering fundamental principles of the Electric Speaking Telephone. |
| | March 10—First complete sentence transmitted by telephone by Bell to Watson, “Mr. Watson, come here; I want you.” Between two rooms at 5 Exeter Place, Boston. |
| | June 25—Bell exhibits his Telephone to the Judges of the Centennial Exhibition at Philadelphia, on which he is awarded the Exhibition’s medal. |
| | August 10—Experimental one-way talk—8 miles, Brantford to Paris, Ontario. |
| | September 1—Contract with Thomas A. Watson for one-half his time—the beginning of telephone research laboratories. |
| | October 9—First experimental two-way telephone conversation between different towns—2 miles, between Boston and Cambridgeport, Mass. |
| | November 26—Conversation over railroad telegraph wires—16 miles, Boston to Salem. |
| 1877, | February 12—Bell’s first public lecture and demonstration of his new invention given before the Essex Institute in Salem, where he had lived and had done some of his experimenting. |
| | April 4—First outdoor line for regular telephone use installed—Boston to Somerville. |
| | May 17—Telephone lines first interconnected by means of an experimental switchboard at 342 Washington Street, Boston. |
| | July 9—“Bell Telephone Co., Gardiner G. Hubbard, Trustee,” the first telephone organization, formed. |
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| | August 1—First stock issue—5,000 shares—dividing interest in the business between seven original stockholders: A. G. Bell, Mrs. Bell, G. G. Hubbard, Mrs. Hubbard, C. E. Hubbard, Thomas Sanders and Thomas A. Watson. |
| | August 10—First Bell telephone employee hired in Boston—Robert W. Devonshire. |
| 1878, | January 28—Opening of first commercial telephone exchange at New Haven, Conn., serving 8 lines and 21 telephones. |
| | May 22—Theodore N. Vail accepts General Managership of Bell Telephone Company. |
| 1879, | March 13—Certificate of Incorporation filed in Boston for National Bell Telephone Company for purpose of unifying telephone development throughout the country. |
| | November 10—Agreement signed by Western Union Telegraph Co. admitting validity of Bell’s basic telephone patents. |
| 1880, | December 31—47,900 Bell telephones in the United States. |
| 1881, | January 1—First telephone dividend, inaugurating a continuous regular series of payments to stockholders. |
| | January 10—Formal opening of telephone service by overhead wire between Boston and Providence—45 miles. A metallic circuit was first successfully tried out on this route by J. J. Carty. |
| 1882, | April 16—Experimental laying of underground telephone cable—5 miles, Attleboro to West Mansfield, Mass. |
| 1884, | March 27—Telephone service opened experimentally between Boston and New York by overhead wires of hard-drawn copper—235 miles. |
| 1885, | March 3—Certificate of Incorporation filed in Albany, N. Y., for the American Telephone and Telegraph Company for the purpose of effecting intercommunication “with one or more points in each and every other city, town or place in said State, and in each and every other of the United States, and in Canada and Mexico—and also by cable and other appropriate means with the rest of the known world.” |