When was the lightbulb first sold?

Several inventors worked on electric lighting, but Thomas Edison developed a practical incandescent bulb with a carbon filament that could burn for many hours. He filed a key patent in 1879 and began commercial sales and installations around 1880. In 1882 his company opened the Pearl Street power station in New York, supplying electricity to light bulbs in nearby buildings and demonstrating a full lighting system. Early bulbs lasted only a few hundred hours and were relatively costly. Over the following decades improvements in filaments, especially the switch to tungsten, made electric light cheap and reliable.