John R. Vile, Encyclopedia of Constitutional Amendments, Proposed Amendments, and Amending Issues, 1789-2002, ABC-CLIO, (ISBN9781851094288, lire en ligne), p. 63
James L. Roark, Michael P. Johnson, Francois Furstenburg, Patricia Cline Cohen, Susan M. Hartmann, Sarah Stage et Sarah E. Igo, The American Promise: A History of the United States, vol. Combined Volume (Kindle), Boston, MA, Bedford/St. Martin's, , Value Edition, 8th éd. (ISBN978-1319208929, OCLC1096495503, lire en ligne), « Chapter 19 The City and Its Workers: 1870–1900 », Kindle Locations 14409–14410