Coal
Part of the Frick Collection Archives Repository
N.P. Hyndman (Pittsburgh, Pa.), 1902, Box: 35, Folder: 38. Henry Clay Frick Papers, Series IV: Receipts, FFP.01.04. Frick Collection Archives.
N.P. Hyndman (Pittsburgh, Pa.), 1902, Box: 35, Folder: 38. Henry Clay Frick Papers, Series IV: Receipts, FFP.01.04. Frick Collection Archives. https://archives.frick.org/repositories/3/archival_objects/7279 Accessed December 10, 2025.
