JUST as the development of an organism, whether plant or animal, is dependent both on the inherent qualities of the organism itself and on its environment, so is the development of a civilization dependent both on the cultural heritage of the settlers and on the physical conditions of the region they occupy. Among these conditions not the least in importance is the situation of the region in relation to the other parts of the civilized world. It must be recognized at the outset that the term "western Pennsylvania" is a vague one and needs definition. The northern, western, and southern boundaries of the region coincide, of course, with those of the state, but there is no general agreement as to the boundary between western Pennsylvania and eastern or, if three divisions are preferred, central Pennsylvania.
From the point of view of physiography, one might choose the divide between the westward and the eastward flowing streams. This has the advantage of running across the state from north to south with approximately one-third of the state to the west; but, except for about forty miles where it coincides with the Allegheny Ridge, it is a very inconspicuous landmark. The Allegheny Ridge itself is more significant and marks the recognized boundary between two physiographic provinces, but as it progresses northward it swings to the east and it fails to reach the northern boundary of the state. From the point of view of history it is even more difficult to locate the eastern boundary of western Pennsylvania because, during the period of settlement, it coincides with the vague and shifting western limit of the settled country. Taking into consideration both the physiographic and the historical points of view and also the desirability of following county lines, it has seemed best to draw the line in an arbitrary manner so as to include Potter, Cameron, Clearfield, Blair, and Bedford counties and all the state west of them within the limits of western Pennsylvania as the term is used in this work. The northeastern sec-