At the remarkable age of 65, Nimrod O'Kelly--Ioner, former blacksmith--made the arduous trek from Missouri along the Oregon Trail in 1845 and became one of the first to stake a claim in the lush Willamette valley. Although he made few improvements to the land, he professed that he had a wife and family back home and thus had a right to 640 acres--one full square mile--of fertile ground. Over the next seven years, settlers continued to arrive, and many of these new neighbors grew suspicious of his entitlement. Slowly they began to encroach on his property. Eventually the dispute boiled over,...