ACKNOWLEDGEMENTS

As always, no scientific or scholarly paper is ever written in a vacuum. Many people, institutions, libraries, and special collections have been drawn upon in the assembling of this essay. The primary library resources were Library of Congress, Washington, D.C.; Enoch Pratt Free Library, Baltimore, Maryland; University of Maryland, College Park, Maryland; and the libraries of the National Museum of Natural History, Smithsonian Institution, Washington, D.C.

Especially helpful were the staff and special collections of the following: Prince George's County Public Library, Maryland Room, Hyattsville, Maryland; District of Columbia Public Library, Washingtonian Collection, Washington, D.C.; and Yale University's Marsh Papers Collection, which I used on microfilm at the American Philosophical Society in Philadelphia, Pennsylvania.

Many people associated with the preservation of the history of Prince George's County, Maryland, gave their time and assistance: Fred DeMarr, Prince George's Historical Society; Susan Helmann and Susan Pearl, Maryland National Capital Park and Planning Commission; and Mary Louise de Sarran, Maryland Historical Trust, Crownsville, Anne Arundel County, Maryland.

Special appreciation goes to those who loaned rare photographic prints and negatives and archival materials: Ms. Janis J. Toennisson, Intermet Corporation; Susan Hellmann and Susan Pearl, Maryland-National Capital Parks and Planning Commission; and Arnold W. "Butch" Norden, Maryland Department of Natural Resources. Walter Belfield, greatgrandson of Charles E. Coffin, kindly lent material from family files.

Robert Louis "Lou" Benson of the Anne Arundel County Historical Society provided information, especially on the Snowden's activities. Ron Smith of Bethlehem Steel helped with early iron smelting resources.

At the Smithsonian Institution, Washington, D.C., I was aided by William Worthington and James Roan of the American History Museum; and by Bob Purdy, Mike Brett-Surman, Chuck Martin, and Nick Hotton of the Department of Paleobiology, National Museum of Natural History.

Finally, I offer my sincere thanks to the staff of the Maryland Geological Survey and most especially Dr. James Reger. Not only did he devote countless hours to the preparation of most of the illustrations as well as the final form of the manuscript, but his dedication to the integrity of the authors' manuscripts is a rare and wonderful quality, has made the work possible, and brought it to fruition during the past year.