Steam and the inexpensive electricity it could produce brought about dramatic technical growth in the United States. Developed during the last century, reliable and efficient steam engines were the forerunners of today's massive generating facilities. A rare survivor of the period, the Pratt facility is the oldest generating plant of its kind in the Northeast and embodies the typical features of engines in a row, open-front marble switchboard, and an observation balcony at street level.
The Georgetown Steam Plant, a surprisingly complete and operable steam power plant after a career of nearly seventy-five years, was built in the early 1900s when Seattle's inexpensive hydroelectric power attracted manufacturers. Much of the power produced at this plant operated the streetcars. It marks the beginning of the end of the reciprocating steam engine's domination in the growing field of electrical energy generation for lighting and power.
The 4,620-horsepower GG1 was primarily a passenger locomotive, routinely operating at over 100 miles per hour, but was used in freight service as well. Conceived by the Pennsylvania Railroad and built by the Baldwin Locomotive Works and General Electric Company, No. 4800 logged nearly 5 million miles in its forty-five-year life. It was the prototype for a 139-unit fleet built during a decade to serve on the PRR's electrified lines, and the only one with a riveted body shell; the remainder were welded.