The smart grid is a key project in the Internet of Things(IOT).The most common definitions of the smart grid in the USA are introduced first followed by its characteristics and advantages.The conceptual model of the smart grid is then described from a systematic perspective from the top layer to the lower layers which consists of different domain layers.The current smart grid projects all over the USA are illustrated.Some smart grid projects and programs are given as examples of the smart grid development by the industry.Finally,the challenges of the smart grid in the USA are summarized in terms of the procedures and technologies. <<