Cooper & Hewitt partners were iron businessmen who purchased ironworks, property, and iron mines. In 1845, a rolling mill complex was incorporated as the Trenton Iron Company, and in 1847 iron mines at Andover, New Jersey, were purchased. The records consist of two payroll sheets from 1848, as well as eighty-two inbound letters, mostly from 1849 to 1850. The letters are primarily operating reports from the superintendent of the Andover mine.

This collection represents materials collected by Cyrus J. Sharer for his research on the iron and steel industry and particularly the world iron ore trade. The main emphasis is on the iron ore trade of the Great Lakes. The period covered, mid-1960s to mid-1980s, was one of crisis and reorganization in the American steel industry and in the lake ore trade, and this is reflected in the records.

The records consist of photocopies of miscellaneous documents of the Empire Steel and Iron Company, the originals of which are in the possession of the National Canal Museum at Easton, Pa. Most of them seem to have come from the Mount Hope site. There is another small collection of miscellaneous materials from the field office of the Mount Hope Mine at the New Jersey Historical Society.

Frederick William Wood (1857-1943) was an executive and engineer in the steel and shipbuilding industries. His papers constitute a major source on the history of the American steel industry in the late nineteenth and early twentieth centuries. The papers are primarily official records of the various companies with which Wood was associated.

Joseph Lincoln Gillson (1895-1964) was the chief geologist for the DuPont Company's Development Department from 1929 to 1960. As chief geologist he traveled all over the world making explorations in search of sulfur, ilmenite, fluorspar, barytes, celestite, and other raw materials, as well as conducting investigations in search of ground water supplies, foundations, and general site studies. This is a small collection that consists of a set of notebooks and related documents from Gillson's time working for the DuPont Company, as well as a set of papers and related documents from consulting projects he did during his retirement.

The Phoenix Steel Company began in the late eighteenth century as a manufacturer of cut nails. It later became a major producer of railroad rails and iron and steel structural members. Their records include minutes (1856-1929); stock ledgers; brief of title papers and property maps; legal and financial correspondence and tax papers; account books; and a works diary.