The Millerstown Iron Company, organized in 1873, constructed the Macungie Furnace in Macungie, Pennsylvania, and was a small anthracite iron company. The microfilmed letterbook documents the business correspondence of the company and includes outgoing correspondence from the Macungie furnace's superintendents.

The Millerstown Iron Company, organized in 1873, constructed the Macungie Furnace in Macungie, Pennsylvania, and was a small anthracite iron company. The minute book records the activities of the directors of the company, primarily concerning company finances and the efforts to raise money by the sale of bonds.