The great early mid-continental highway, known as the Oregon Trail or the Overland Trail, was by way of the Missouri up the Platte Valley, thence across the mountains. We know more of this route because it was not discontinued, but came steadily more and more into use, for one reason after another. The fur traders used it, the Forty-Niners used it, the cattlemen used it in part, the railroads used it; and, lastly, the settlers and farmers used it most of all. In physical features the Platte River route was similar to that of the Arkansas Valley. Each at its eastern extremity, for a few days' travel, passed over the rolling grass-covered and flower-besprinkled prairies ere it broke into the high and dry lands of the Plains, with their green or grey or brown covering of practically flowerless short grasses. But between the two trails of the Arkansas and the Platte there existed certain wide differences. At the middle of the nineteenth century the two trails were quite distinct in personnel, if that word may be used. The Santa Fe Trail showed Spanish influences; that of the Platte Valley remained far more nearly American. Thus far the frontier had always been altering the man who came to it; and, indirectly, always altering those who dwelt back of the frontier, nearer to the Appalachians or the Atlantic. A new people now was in process of formation--a people born of a new environment. America and the American were conceiving. There was soon to be born, soon swiftly to grow, a new and lasting type of man. Man changes an environment only by bringing into it new or better transportation. Environment changes man. Here in the midcontinent, at the mid-century, the frontier and the ways of the frontier were writing their imprint on the human product of our land. The first great caravans of the Platte Valley, when the wagon-trains went out hundreds strong, were not the same as the scattering cavalcade of the fur hunters, not the same as the ox-trains and mule-trains of the Santa Fe traffic. The men who wore deepest the wheel marks of the Oregon Trail were neither trading nor trapping men, but homebuilding men--the first real emigrants to go West with the intent of making homes beyond the Rockies. The Oregon Trail had been laid out by the explorers of the fur trade. Zealous missionaries had made their way over the trail in the thirties. The Argonauts of '49 passed over it and left it only after crossing the Rockies. But, before gold in California was dreamed of, there had come back to the States reports of lands rich in resources other than gold, lying in the far Northwest, beyond the great mountain ranges and, before the Forty-Niners were heard of, farmers, home-builders, emigrants, men with their families, men with their household goods, were steadily passing out for the far-off and unknown country of Oregon.