Northumberland: Where Edison Lit the World's First Three-Wire Grid

Northumberland, Pennsylvania, sits at the fork where the North and West Branches of the Susquehanna River meet. Joseph Priestley lived here and died here. But the town has a second claim that is less famous and arguably just as consequential.

On July fourth, eighteen eighty-three, Thomas Edison's crew switched on the first successful three-wire electric lighting system, in Sunbury, just across the river. The system ran overhead conductors through the streets and used electro-chemical meters to charge customers by exactly how much electricity they consumed. Edison himself was on site directing the work and later stated that Sunbury, the neighboring town across the river, was the first place on earth to be illuminated by the three-wire system through overhead street conductors.

The three-wire design is the direct ancestor of the electrical grid that powers every building you will pass on this drive.