The Portland Company commenced operations in 1846 in Portland, Maine, under the leadership of John A. Poor. It was founded primarily to manufacture railroad locomotives for the Atlantic & St. Lawrence Railroad. The company played a major role in the economy and development of the state of Maine and continued in business until 1982, producing a wide range of cast-metal and fabricated products.

The Portland Company manufactured a total of six hundred thirty steam locomotives, starting in 1848, along with hundreds of railroad cars, boilers, marine engines, ships, steam fire engines, elevators, and paper and textile mill equipment. Locomotives, ships, and cannons were built for the Civil War, and munitions were manufactured for both world wars. Later, the Portland Company produced snowplows, nuclear plant components, and common castings from manhole covers to streetlights. In the early 1900s, the company sold five makes of new automobiles and trucks. In this rich photographic history, the Portland Company and the city of Portland, with its great waterfront and industrial heritage, come to life.