A book as long as this, dealing with the modern as well as the current history of Philadelphia and other cities, requires a great deal of help. The list of people to whom I owe a debt begins with three fellow historians. Harry Silcox, principal of Abraham Lincoln High School, first brought the William Henry Dorsey Collection to my attention, and again shared his knowledge of Philadelphia's 19th-century black history, his collections, and his own published and unpublished work. Charles R. Blockson, curator of the Blockson Collection of Afro-Americana at Temple University, has been a matchless source of information about the men and women of Dorsey's generation and their descendants. Charles A. Hardy III, too, who has interviewed dozens of surviving veterans of "The Great Migration" of the 1910s and 1920s, has helped to locate individual people as well as to put the earlier period in context.
The staff of the Historical Society of Pennsylvania, which has inherited the remaining records of Dorsey's American Negro Historical Society, has been, as always, professional and helpful; so have the several Philadelphia county and city agencies which contain the records of the past, notably the Municipal Archives under the direction of Ward Childs. Victoria Parker, Secretary of St. Thomas Church, combed the church's archives for relevant records. David Assolino, of the Van Pelt Library of the University of Pennsylvania, is courteous curator of the census and other raw records collected by the Philadelphia Social History Project, which under the direction of Theodore Hershberg in the 1970s did so much to influence the direction of urban history generally.
Academic Vice President Vernon Clark and librarian Karen Humbert, of Cheyney University, helped make the whole of the Dorsey Collection accessible; Dorothy Wesley-Porter and Sulayman Clark helped to unravel its history.