The Journal of Samuel Maclay is one man's account of a 1790 surveying expedition, commissioned by the Supreme Executive Council of Pennsylvania, to explore the newly purchased land in northwestern Pennsylvania, including the headwaters of the west branch of the Susquehanna, the Sinnemahoning, and the Allegheny Rivers. The journal, published in 1887 with ample historical annotations by John F. Meginness, provides a richly detailed record of Maclay's travels in the "New Purchase" over five months, ending along the Juniata River in the Kishacoquillas Valley. It preserves both the...