From the perspective of historians of science in the 1970s, the history of science in the United States might well have constituted a minor thread in their reading. The field's focus on events before the nineteenth century and on the development of sciences in the United Kingdom and Europe easily diverted focus from the United States (as well as many other parts of the world). However, in more recent scholarship on the history of science, the United States is a major presence – a product both of a growing community of professional historians of science in the United States and of a broader shift within the field towards events in the twentieth century. As the history of American science has gained stature within the history of science, so too has it attempted to gain a place within American history writ large. Reflecting this ambition, Wiley Blackwell have commissioned A Companion to the History of American Science as part of a series of Companions to American History. It is intended as a point of entry for those unfamiliar with the field, as well as a reference for historians of science.

The collection consists of essays of two types: an alphabetically arranged series of essays on different scientific disciplines, and a series of essays with no apparent thematic order on different ‘topics’ that emphasize the relation of different sciences to American society. ‘Genetics’, ‘Medical genetics’ and ‘Molecular and cellular biology’ are disciplines, for example, while ‘Eugenics’ or ‘Biotechnology’ are topics. The essays reach back to the eighteenth century in some instances, but the focus of the collection is on the nineteenth and twentieth centuries. Both the disciplinary and the topical essays within this reviewer's areas of competence did well in providing cues to important milestones and in illuminating historiographic questions. The bibliographic essays included with the overviews are also a very useful research tool.

Beyond these practical functions the Companion provides an opportunity to reflect on the rapid growth of the history of American science as a sub-field within the history of science. The editors of this volume place their efforts in the third ‘wave’ of collections seeking to capture the unique character of the history of science in America. Prior iterations have included The Sciences in American Context (1979), Historical Writing on American Science (1985) and The American Development of Biology (1991). After a point, single volumes could not contain the amount of scholarship produced on the history of science in the United States – a function of the vast expansion of science after the Second World War and the growing attention paid by historians of science to events in the late twentieth century, as highlighted, for example, by Science in the American Century (2013).

The emphasis on American science is more than the recognition of an active sub-field. The editors of the Companion foreground a cultural approach to the history of science, and the organization of their volume reflects their conviction that a distinct cultural ‘style’ marks the history of science in the United States. The entries are powerfully shaped by a commitment to the idea that the cultural dimension of science matters deeply to its practice and development – hence the importance of nationality as a descriptor rather than a mere locator (p. 3). Following this emphasis, the volume contains frequent references to processes such as professionalization, application, militarization, commercialization or popularization. However, although it is certainly fair to argue that each of these processes follows particular national contexts, it is not especially clear how or why a particular process would be different in the case of American science than in the history of British, German or Russian science. The occasional cross-national comparison may help highlight the contingency of processes that seem unremarkable, or inevitable, in a given national frame.

Placing the practice of science within its particular local contexts represents a major accomplishment for the history of science thus far. However, recent discussions of how to write the history-of-science field have reminded us of the importance of remaining aware of the need to seek out narrative strategies that avoid taking the frame of the nation state for granted. This is certainly true of American science, which at first took root in the context of a growing continental empire and later expanded in the context of a series of global military conflicts – both hot and cold. A national frame might cause one to underestimate the transnational movements of scientific ideas and scientists that shaped American science, especially in the twentieth century. The development of physics and molecular biology, for example, cannot be understood absent an understanding of the flows of scientists dislocated by the prelude and aftermath of the Second World War (which, in fairness, the authors of these two entries on this topic in the Companion do mention).

A volume on the history of American science also raises the question of the disciplinary orientations of those who study science in the United States. As several contributors to the Companion note, historians do not hold a monopoly on the study of science in America, especially as the scope of historians expands to events in the later twentieth century. To what degree might the study of American science be informed by developments in the philosophy of science, science and technology studies, or historiographic innovations in American history (such as the study of capitalism or transnationalism) more generally? That one is left with these questions from paging through the Companion, however, is a sign of the service it does in capturing the extraordinary ferment in the history of American science and its importance not only to the history of science, but to the history of the United States as a whole. In addition to acting as a gateway into the history of science for American historians, the Companion will surely reward consultation by experts in the history of science.