And now the fort which had so long looked down upon the canoes of the Indians and traders saw on its two rivers a new procession. Flatboats, steamboats, and canoes bore upstream the hardy pioneers and their families, and returned loaded with the products of the farm and the forest. The post which could have successfully resisted the attack of Indian warriors, or even the siege of a civilized enemy was to fall before the invasion of the pioneers. The frontier had suddenly leaped far to the westward. In 1858, when the troops were withdrawn, there was no need of an establishment such as had existed during the first forty years. It was the passing of Old Fort Snelling which for so many years had been the remotest outpost of American law. The development of the Northwest was not brought about by the spectacular and romantic incidents which the chroniclers loved to record. So gradual was its progress that the factors contributing to it can be seen only in the perspective of fifty years. It was the result of the monotonous details of the life of the fur trader who was the unwitting explorer of the Northwest, and the forerunner of the permanent resident. The routine duties of garrison life and expeditions to the Indian country, often barren of any visible result, added to its progress, as also did the weary marches of the explorer and the minute notations of the scientist who accompanied him. The patient sacrifices of the missionary who toiled at unaccustomed labors in the half-cleared cornfield and taught his primitive pupils in the log mission-house, introduced a new civilization. The daily contact of the Indian and the white man at the fort and agency were prophetic of a new relationship between the two races. But because these events were so commonplace the contemporary chroniclers have bequeathed only a brief though eloquent epitome of this old Mississippi River post. It was the exception and not the rule to note that a company of soldiers was up the river watching the movements of the Indians, that a missionary had been presented with a ham, or that an explorer took with him so many vegetables from the gardens of the fort that the gunwale of his boat was brought within four inches of the water. But such are the stray references which indicate the almost complete dependence upon the fort of all the factors in the development of the Northwest.