The history of the communities of Pennsylvania affords a convenient initiation into much of the complex religious and ecclesiastical history of Europe. Penn brought the Quakers and other fine English stock from the middle and north of England for reasons that go to the very heart of the English life of the seventeenth century. A little later the Protestant Germans of the Palatinate came in great numbers, impelled by motives to understand which is to find oneself essentially comprehending the conditions of Church and State that so disturbed and harassed Western Europe for a long period. Thus, to study the great city of Philadelphia in its origins, its later accretions and its existing conditions, is to find inviting avenues leading into many fields of historical inquiry both of the new world and the old. What single spot could one find anywhere that would more naturally stimulate the study of political and economic history in the nineteenth century than old Castle Garden at the lower end of New York City, through which millions upon millions of immigrants have entered the Western world to find contentment and prosperity? Many of these came from Ireland; and the municipal life of New York City has been profoundly affected by that fact. To answer the question why these people left Ireland and, in leaving, why their destination was New York rather than some port in the British colonies, is to review the history of the Irish land system, the Irish Church and the political administration of Ireland for several generations. An enormous element of the present population of New York, as well as of the country at large, is made up of a comparatively recent German immigration, to understand which one must learn something of the German revolutionary movement of 1848, the growth of German militarism and the conditions under which educational progress in Germany has outstripped the average material prosperity. Still more recently there has been a huge immigration of Russian Jews, with local effects of a most marked character in the city of New York. To know why these Jews have come is to look into racial, political, and economic conditions throughout the great empire of the Czar. To study the main routes of communication in a region like our Middle States is to gain an insight into the relations of physical conditions to historical development that will be of no little use in the study of other origins and remoter periods. It would be hard to exaggerate the importance, for instance, of the part that the Hudson River has played in the history of the Western Hemisphere since its discovery and settlement by the Europeans. The route by way of the Hudson, Lake George and Lake Champlain afforded in the early times the one interior passage to the St. Lawrence from the settlements on our seaboard.