The study of the history of cartography in the United States has been profoundly shaped by the peculiar American institution sometimes known as the 'treasure house'. These libraries, located in major metropolitan areas and at prestigious universities, were created through the philanthropy of businessmen of local and national significance, most of whom also collected maps and books. The collecting patterns of these philanthropists and the institutions they helped to found emphasized materials (including maps) relating to American history and culture before 1800. This emphasis on pre-nineteenth century holdings tended to marginalize the historical study of most post-1800 cartography in the United States until the middle of the twentieth century. At the same time, as a case study of Chicago's Newberry Library shows, the development of these collections was flavoured by the civic and regional pride of their host communities and the aspirations to be regional, national and global metropolises.