The records of the Phoenix Iron Company includes minutes (1856-1929); stock ledgers; brief of title papers and property maps; legal and financial correspondence and tax papers. Account books (1856-1938) are incomplete. A works diary (1870-1879) is primarily concerned with weather, but includes observations on events of the day during the troubled period of the late 1870s. A notebook of Isaac Reeves is primarily devoted to geometrical and engineering formulas, with a few notes and sketches on minor construction projects around the works.

The operations of Reeves & Whitaker; Reeves, Buck & Company; and Reeves, Abbott & Company are represented only by account books, which show the financial aspects of transactions but give little operating detail. The Spring Mill Furnace is represented by accounting blotters for the period of David Reeves' lease (1855-1866). The records do permit identifying major customers and amounts paid for orders of nails, railroad rails, etc.

Patent papers include original patent letters, correspondence and a few drawings. The patents are those obtained by members of the company for improvements in the manufacture of structural iron, for railroad turntables, rails, and fittings, plus domestic and foreign patents for the Griffen gun. Engineering records include specifications and handbooks, including an illustrated handbook on Phoenix Column construction. From the 1950s there is a survey for the construction of the seamless tube mill.

A discharge register (1901-1930) gives names of employees discharged, with date, department and cause.

Shop order books (1860-1937) are simple lists of orders for parts. Shop improvement ledgers (1899-1940) show costs of additions and modifications to plant.

Correspondence includes the following series: managers (1881-1929); shop (1898-1948); safety (1916-1937); steel plant (1897-1947); and new mill (1897-1947). It is almost entirely concerned with product orders and typically take the form of ordering the shop to produce a particular component, many of which are for use within the plant. Most of the letters contain sketches of the part to be produced. Inbound letters (1888-1937) are from customers and suppliers and are chiefly concerned with machinery for use within the plant.

A series of inter-office correspondence and memos (1941-1960) covers the company's period of decline under Barium ownership. Much of the correspondence concerns steel being supplied to the Phoenix Bridge Company as well as that company's bridge projects. There are reports of stocks on hand, jobs completed or pending wages paid, along with notes on salaries and pensions. The Barium period is represented by printed annual reports of the Barium Steel Corporation; the Barium Newsletter; some minutes of management meetings; production and cost statistics; and progress reports. There is some discussion of competition between the Phoenix Bridge Company and rival firms over bridge contracts and Barium's attempts to secure defense contracts. The Central Iron & Steel Company is represented by daily reports of its sales representatives (1961) listing calls on potential customers.

The records of the Phoenix Bridge Company (Accession 1179) have been merged with this collection. These records consist of 153 engineering drawings of bridges, railroad turntables, highway viaducts, warehouses, track spans, electric power stations, factories and foundries, tunnels, elevated train tracks, and piers.

The miscellany (Accession 909) consists of a small collection of material received independently of the main body of records. It includes the annual reports of the general superintendent (1872-1922); a sales book of the George M. Newhall Engineering Company of Philadelphia (1904-1911); a typescript company history by Catherine S. Sisto (1950); a photographic album of pictures of a cantilever bridge over the Colorado River at Needles, Calif., built by the Phoenix Bridge Company, ca. 1890; and a sample of letters received by president Samuel J. Reeves (1872-1878), primarily concerned with the Girard Avenue Bridge contract, the Second Ave. El. contract, retrenchment problems associated with the depression; and a report on the Warwick and Hopewell Iron mines in Chester County and the Jones Mine in Berks County.

A second collection of miscellany (Accession 683) consists of 335 items from 1844-1875, including correspondence concerning orders for iron and deliveries to railroads. Also included are bills, drawings and calculations, and certificates for Civil War prize money on cotton captured at sea by the U.S.S. Quaker City.