Phil Mossman's Money of the American Colonies and Confederations: A Numismatic, Economic and Historical Correlation (ANS 1993) is the most important book of the twentieth century on colonial American numismatics. Borrowing some lines from an introduction I am contributing to a forthcoming book, I describe the work as follows:

Phil's book explained colonial coinage in terms of economic history. From the macroeconomic perspective he discussed which coins were in circulation and how they were used, thus placing the confusing assemblage of colonial coinage in an historical context. From a microeconomic perspective he explained the importance of coin weight as a fundamental factor in the profitability and success of a mint and from this perspective was able to classify coin varieties by weight distribution thus providing new insights on minting techniques and possible counterfeits. The book is extremely well written, covering two hundred years of numismatics in America in a clear and thoughtful manner.