The Albert T. Keller photographs series consists of over 2,000 images taken by Albert T. Keller, an avocational historian of the iron industry, who was the Chief Engineer of Construction for the Bethlehem Steel Company in Bethlehem, Pennsylvania. These photographs depict the sites or remains of early ironworks in the mid-Atlantic states and New England states, as well as Alabama, Colorado, Connecticut, Illinois, Indiana, Kentucky, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, New Hamphire, New Jersey, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, Wisconsin and a few foreign sites. The foreign countries represented are Canada, England and Wales. Keller photographed these places in the 1930s. Also included in this series are over fifty blast furnace complexes. Many of these were extant by the 1930s when the photographs were made and collected, but some are of active company sites. There is a particularly nice collection of Bethlehem Steel Company items showing the Sparrows Point plant. This series is arranged alphabetically.

Keller sometimes made notes on scraps of paper and recycled envelopes listing book citations used to research the dates of the furnaces. These tracings have been copied on to new envelopes when the collection was rehoused or maintained in their original format. The Hagley Library has some of the volumes that Keller referred to. One often cited is geologist Peter Lesley's 1859 work, The Iron Manufacturer's Guide to the Furnaces, Forges and Rolling Mills of the United States [Published Collections TN403 A5 L6]. Keller also cited Documents Relating to the Manufacture of Iron in Pennsylvania: Published on behalf of the Convention of Ironmasters, which met in Philadelphia, on the twentieth of December, 1849 [Published Collections TS300 I7 1849] and another eighteenth century book, A Concise History of the Iron Manufacture of the American Colonies up to the Revolution, and of Pennsylvania until the present time by John Pearse [Published Collections TN704U5 P3].