1870May 28 Older brother Melville Bell dies of tuberculosis at the age of 25.
July-August Alexander Graham Bell, his parents, and his sister-in-law, Carrie Bell, emigrate to Canada and settle in Brantford, Ontario.
1871April Moving to Boston, Alexander Graham Bell begins teaching at the Boston School for Deaf Mutes.
1872March-June Alexander Graham Bell teaches at the Clarke School for the Deaf in Boston and at the American Asylum for the Deaf in Hartford, Connecticut.
April 8 Alexander Graham Bell meets Boston attorney Gardiner Greene Hubbard, who will become one of his financial backers and his father-in-law.
Fall Alexander Graham Bell opens his School of Vocal Physiology in Boston and starts experimenting with the multiple telegraph. Brochure for Bell's School of Vocal Physiology
1873Boston University appoints Bell Professor of Vocal Physiology and Elocution at its School of Oratory. Mabel Hubbard, his future wife, becomes one of his private pupils.
1874Spring Alexander Graham Bell conducts acoustics experiments at the Massachusetts Institute of Technology. He and Clarence Blake, a Boston ear specialist, begin experimenting with the mechanics of the human ear and the phonautograph, a device that could translate sound vibrations into visible tracings.
Summer In Brantford, Ontario, Bell first conceives of the idea for the telephone. (Bell's original sketch of the telephone) Bell meets Thomas Watson, a young electrician who would become his assistant, at Charles Williams's electrician shop in Boston.
1875January Watson begins working with Bell more regularly.
February Thomas Sanders, a wealthy leather merchant whose deaf son studied with Bell, and Gardiner Greene Hubbard enter into a formal partnership with Bell in which they provide financial backing for his inventions.
March 1-2 Alexander Graham Bell visits noted scientist Joseph Henry at the Smithsonian Institution and explains to him his idea for the telephone. Henry recognizes the significance of Bell's work and offers him encouragement.
November 25 Mabel Hubbard and Bell become engaged to be married.
1876February 14 Bell's telephone patent application is filed at the United States Patent Office; Elisha Gray's attorney files a caveat for a telephone just a few hours later.
March 7 United States Patent No. 174,465 is officially issued for Bell's telephone.
March 10 Intelligible human speech is heard over the telephone for the first time when Bell calls to Watson, "Mr. Watson.Come here. I want to see you."
June 25 Bell demonstrates the telephone for Sir William Thomson (Baron Kelvin) and Emperor Pedro II of Brazil at the Centennial Exhibition in Philadelphia.
1877July 9 Bell, Gardiner Greene Hubbard, Thomas Sanders, and Thomas Watson form the Bell Telephone Company.
July 11 Mabel Hubbard and Bell are married.
August 4 Bell and his wife leave for England and remain there for a year.
1878January 14 Alexander Graham Bell demonstrates the telephone for Queen Victoria.
May 8 Elsie May Bell, a daughter, is born.
September 12 Patent litigation involving the Bell Telephone Company against Western Union Telegraph Company and Elisha Gray begins.
1879February-March The Bell Telephone Company merges with the New England Telephone Company to become the National Bell Telephone Company.
November 10 Western Union and the National Bell Telephone Company reach a settlement.