The Evolution of American Legislatures is a gem. Peverill Squire’s canvas is vast; he seeks to “reveal the evolutionary line that ties American legislatures across four centuries” (p. 2). This daunting project is more in line with grand historical narratives rather than the far more narrowly tailored analysis found in much of the political science literature.

Squire traces an evolutionary line across legislative bodies. The original thirteen state legislatures (and Vermont) are descendants of the thirteen colonial legislatures. They, in turn, provided the frameworks for The Constitutional Congress (and the Kentucky legislature). At that point most new states entering the Union derived from territories. These new state legislatures had previous incarnations as territorial legislatures. They all copied existing models from the first fifteen states. The Civil War did not disrupt the evolutionary flow; the Confederate state legislatures operated in much the same fashion as when they were part of the Union. A second evolutionary line of legislatures proved far less durable: The Continental Congress was an antecedent to the short-lived provincial congresses and the Confederation Congress.

Squire provides copious evidence that legislatures evolved because of organizational and not partisan issues. Political parties played little to no role in most newly established legislatures from colonial times through the 19^th century. He shows that standing committees became a well-established feature of state legislatures long before a similar system developed in the U.S. Congress. He documents just how extreme the turnover was in many legislative bodies until the 20^th century. This data is useful for evaluating existing hypotheses about legislative development. Squire provides a corrective to scholars of Congress who sometimes view institutional change as completely endogenous. A number of adaptations in the U.S. Congress were simply borrowed from state legislative bodies.

One of Squire’s most fascinating findings is how overwhelming the impulse is to create legislatures. What connects “odd cases” in American history of quasi-independent or disputed regions is that the inhabitants of those areas established their own legislative bodies. A partial list of examples include: the Vermont Legislature, the Kentucky General Assembly, the Congress of the Texas Republic, the General Assembly of the State of Franklin, the General Assembly of the Deseret, the Legislative Assembly of San Francisco, and the General Assembly of the Indian Stream Republic.

A monumental amount of original research was necessary in order to write this book—no wonder Squire thanks the librarians who helped him track down such esoteric sources. The extensive bibliography is a product of extensive detective work and will be a useful guide for students of legislatures. Squire provides a consistent stream of anecdotes that make the book something of a page-turner. We learn that the Pennsylvania Assembly as late as the 1750s operated in a manner similar to that of a Quaker meeting: “silences were common as members waited for the inspiration to speak” and the Assembly Speaker might rather seek to get a “sense” of the body rather than call for a vote (p. 60). In New Mexico business was conducted in Spanish throughout the 19^th century and even as early as 1899, interpreters were provided for the minority of legislators who spoke English. In the Wisconsin territorial legislature, a lawmaker shot and killed another legislator during a heated debate on the floor about a gubernatorial nomination. The murderer was acquitted of manslaughter by the jury and was elected again to the Wisconsin legislative assembly. He later moved to California where he again won election as a state legislator. In most western territory and state legislatures, the vast majority of elected representatives were under thirty-five. The legislature in the Dakota Territory resembled a “college fraternity meeting” with the associated drunken antics (p. 109). Legislators, especially in the territories, were not well paid, lived and met in very rough venues, and incurred dangers in their travels. Legislators are recorded drowning, getting killed by Apaches, and suffering other grievous fates when travelling to or leaving a meeting of the state legislature.

The book is not particularly theory-driven, although many of the patterns identified by Squire are important insights. On pages 7–8 he situates the trajectory of American legislative bodies as one of “multi-faceted” diffusion, as opposed to that of a “hegemon” model and that the “mechanism” for the diffusion is some sort of learning model. On page 14 “path dependence” is referenced as conceptual framework, but its usage is not consistent with the usage of “path-dependence” as applied by Paul Pierson (2000, 2004), Jacob Hacker (1998, 2002), and others.

The seventh and eighth chapters of the book discuss the professionalizing of the state legislatures since 1900 and possibilities for future evolution. These chapters are not as satisfying. This is likely, in part, because the same modes of analysis deployed in earlier chapters yield less analytic leverage for the 20^th century. For instance, political parties probably become more important to the structure of state legislative bodies; however, Squire does not sufficiently take political parties into account in his narrative. Another example is that while Squire provides detailed analysis of changes in the salaries of state legislators, he does not look at other forms of compensation such as fringe benefits. In Pennsylvania, for instance, legislators increased their pensions high enough so that long-serving members can get paid more when retired than when actively serving. It is possible that Squire’s focus on salary changes could be misleading and that total compensation needs to be evaluated for recent decades.

Squire concludes that state legislatures will continue to evolve because of the external pressures placed on them—a feature consistent across four-hundred years. It is far more challenging to develop granular conclusions because there are few discernible trends concerning the main variables of interest to Squire. For instance, salaries have increased in some legislatures and not others, some are becoming more professionalized and some less, and there is no way to mix and match the states to find consistent trends. Squire, by necessity, avoids extended discussions of the policy issues debated and the laws enacted by the legislatures. Also there is little discussion of campaigns, elections, and the role of interest groups. If generalizable conclusions about the future course of legislatures are to be found, these additional factors almost certainly need fuller consideration.

Squire effectively makes the argument that legislative bodies should be understood in accordance to an evolutionary frame. His choice to survey legislatures across such a vast swath of time allows him to reach conclusions that a narrower approach would obscure. His thorough scholarship and attention to detail is most commendable. The book is also an entertaining read and a must for anyone interested in the minutiae of American political history. Squire’s study is an important contribution to the historical scholarship on legislatures and should be consulted as a standard work in this field of study.