Thales, a Greek, found out that when amber is rubbed against silk it is electrically charged and attracts objects.
William Gilbert derived the word from the Greek word for amber, "elektron".
Ben Franklin tied a key to a kite string during a thunderstorm, and proved that static electricity and lightning were the same thing.
Alessandro Volta (Italy) invented the electric battery. The word "volt" was named after him.
Sir Humphry Davy (England) invented the first effective lamp. The arc lamp was a piece of carbon that glowed when connected by wires to a battery.
Gerog Ohm defined the relationship between power, voltage, current, and resistance in Ohm's Law (Ohm's Law - Voltage = Current x Resistance).
Thomas Davenport invented the electric motor which is today used in appliances.
James Prescott Joule showed that energy is conserved in electrical circuits involving current flow, thermal heating, and chemical transformations (Joule, the unit of measurement for thermal energy, was named in his honor).
Samuel Morse invented the electric telegraph, which is a machine that could send messages long distances across wires.
Joseph Swan (England) invented the first incandescent lightbulb (also called an electric lamp). His lightbulb burned out quickly.