The soil and climate of the St. Lawrence Valley are both rather against the rapid development of agriculture, requiring far more labor to make them arable, and giving a more limited return than do the more southern soils; so that, despite the very great advantage which came from the peculiarly open nature of this path into the interior of the continent, the French did not succeed in maintaining themselves there until its great military advantages could be turned to profit. At the present time the existence of railways has greatly lessened the value of geography as a factor in military movements, and the St. Lawrence, closed as it is for nearly half a year by ice, has no longer any military importance. As it is, we may be surprised that it has not played a more important part in the military history of the continent than it has done. We cannot avoid the conclusion that if the conditions had been reversed, and the English settlements had occupied the Valley of the St. Lawrence, and the French colonies the country to the southward, the English colonists would have made use of its advantages in a more effective way. The settlements at the mouth of the Mississippi did not come into the hands of the French until a late day; but the use they made of this, the easiest navigated of all the great American rivers, was considerable. These settlements were pushed up the valley of the main stream and its greater tributaries, until they practically controlled the larger part of the shores of the main waters. The swift current of the Mississippi and its tributaries made ascending navigation difficult and costly. It was, in fact, only with small cargoes in little boats propelled by poles, or with the aid of sails when the winds favored, that the stream could be mounted. The effective navigation was downward towards the mouth. By way of the Mississippi the French power worked into the centre of the continent far more rapidly than by the St. Lawrence route; indeed, the advance was so rapid that if these Gallic settlements had not been overwhelmed by the stronger tide of the English people getting across the Alleghanies, a few years would have given them a chance to fix their institutions and population in this valley.