August 22 - The Overland Telegraph is completed in Australia, providing a telegraphic link between Australia and the rest of the world for the first time.
Women's suffrage: In defiance of the law, American suffragist Susan B. Anthony votes for the first time (on November 18 she was served an arrest warrant and in the subsequent trial she was fined $100 - she never paid the fine).
November 9 - Great Boston Fire of 1872: In Boston, Massachusetts, a large fire begins to burn on Lincoln Street (the two day event destroyed about 65 acres (0.3 km²) of city, 776 buildings, much of the financial district and caused US$60 million in damage).