One of the leading contributors of historical articles to ME over the past fifty years was Fritz Hirschfeld. In preparation for the United States' bicentennial year in 1976, the editors of Mechanical Engineering contracted with engineer-historian Hirschfeld for a series of articles on the county's early engineering history. Just a few years later, as the Society was nearing its centennial in 1880, the editors again turned to Hirschfeld and asked him to write a series of articles about the founding of ASME and important early mechanical engineers. Hirschfeld's articles, collected here, provide the foundation for the early portion of this volume. Building upon Hirschfeld's foundation, we selected a wide assortment of other articles about aspects of mechanical engineering history in the United States from the Revolutionary War until recent times. We largely limited our selections to those articles published in Mechanical Engineering magazine during the last fifty years (i.e., 1971-2021). Even for this period, the volume does not include all such articles due to limitations in length and editorial judgments. For instance, some articles duplicated coverage of specific events or innovations. In such cases we picked what we deemed the best, or most comprehensive of overlapping articles. We also decided to focus this volume on the history of mechanical engineering in America. We thus excluded articles on historical developments largely occurring outside the United States. At some future time, we may "harvest" both pre-1971 ME articles and unselected post-1971 articles, as well as articles focusing on non-American mechanical engineering achievements, for a separate collection or collections. Of the more than seventy articles collected in this volume, well over ninety per cent were drawn from issues of ME published during the past fifty years. Five pieces, however, were drawn from outside that chronological limit or from other sources. We have, for example, included a 1933 biographical article from ME about American engineer George H. Corliss. Corliss's innovations in the design and manufacture of steam engines and related devices helped establish the United States as a major player in the manufacture of prime movers. Corliss was considered by his contemporaries to be such a significant figure in mechanical engineering circles in the United States that we elected to include him. He was, after all, asked to serve as the first president of ASME-an offer which he declined. A second exception is another biographical article, one on Edwin Reynolds, a significant steam engine designer. It was authored by Thomas Fehring, one of the editors of this volume. Reynolds worked for a time for the Corliss Steam Engine Company, as did other notable American engineers such as Erasmus Darwin Leavitt (second president of ASME) and Alexander L. Holley (one of the founders of the Society), before moving to Allis-Chalmers. Reynolds made significant improvements in steam engine design. He was president of ASME in 1902-03, and three of his steam engines have been designated as Historic Mechanical Engineering Landmarks by the Society.