This map shows the location (in red) of the damage of the Great fire of Portland, 1866. This fire was caused by fireworks during the celebration of July 4th.

To ensure that Portland would never again experience a tragedy like the Great Fire, Portland installed a fire alarm signal system in 1867. The mayor also signed a contract in 1868 to pipe in water from Sebago Lake in order to add to the city's available water supply.