The link between history, institutions and social action defines a dimension of analysis which has found fertile ground for development in American Historical Sociology. Over a period of about 40 years the topic of social change has been faced in a comparative perspective with at least three different approaches. In the 60s and 70s the comparative perspective was strong and corresponded to an instrumental use of history. In the following years the "comparison" appeared to be more controlled, that is less easy to make from the point of view of the methods as well as of the results. These two phases were followed by a third one in which the comparative perspective lost ground being weakened by the debate concerning the theoretical-conceptual apparatus and the instrumenst to be used. This means the prevailing of a new notion of history seen as a process, a sequence of events. As a consequence the analysis no longer considers similar or dissimilar national paths, nor similar events distant in time and spice, but a chain of events taking place within particular institutonal, as well as social and territorial, contextes. The sociology that emerges from the new conception highlights the link between the perspective of a micro-social analysis and that of a macro-social one, supporting the idea that historical dimension represents not only a methodological reference point but a theoretical base on which to build.