An ‘analytic narrative’ is the presentation of crucial historical events, using the intuitions of rational choice theory, to clarify the motivations and beliefs of the principal actors. This article attempts to understand a dilemma embedded in the Declaration of Independence: the expected costs of war against Britain far exceeded any possible benefits, if these are construed simply as the removal of colonial taxation. Furthermore, war against Britain necessitated an alliance with a potential aggressive power, France. An analysis is presented indicating that the benefits also included the enormous reward of the west and the ‘costs’ incorporated possible future aggression by France and Spain. The narrative is extended to the Ratification of the Constitution in 1787, to suggest that the Federalists, and Madison, justifiably feared Spanish aggression in the Mississippi Valley. In the 1790s, consensus (about credible threats by the European powers) fragmented, and this led to entirely different policy preferences by Federalists and Jeffersonian Republicans. Napoleon's imperial intentions in Louisiana were, however, thwarted by the defeat of the French forces in Haiti in 1802–03. The result was the Louisiana Purchase of 1803–04.While the necessary causes of these various constitutional transformations can be appreciated, there appears to be an element of contingency, or happenstance, embedded in the sufficient causes. The purpose of the exercise is to attempt to understand the possibly chaotic basis of rapid institutional change.