The friendly spirit in which Webster and Ashburton had carried on their negotiations inaugurated a period of reasonable amity between their two nations. The United States annexed Texas without serious protest; in spite of the clamor for "fifty-four forty or fight," Oregon was divided peacefully; and England did not take advantage of the war with Mexico. Each of these events, however, added to American territory, and these additions gave prominence to a new and vexing problem. The United States was now planted solidly upon the Pacific, and its borders were practically those to which Adams had looked forward. Natural and unified as this area looks upon the map and actually is today, in 1850 the extent of territorial expansion had overreached the means of transportation. The Great Plains, then regarded as the Great American Desert, and the Rockies presented impossible barriers to all but adventurous individuals. These men, uniting in bands for self-protection and taking their lives in their hands, were able with good luck to take themselves but little else across this central region and the western barrier. All ordinary communication, all mail and all freight, must go by sea. The United States was actually divided into two very unequal parts, and California and Oregon were geographically far distant colonies. The ocean highroad belonged to the United States in common with all nations, but it took American ships to the opposite ends of the earth. No regular shuttle of traffic sufficient to weave the nation together could be expected to pass Cape Horn at every throw. The natural route lay obviously through the Caribbean, across some one of the isthmuses, and up the Pacific coast. Here however, the United States would have to use territory belonging to other nations, and to obtain the right of transit and security agreement was necessary. All these isthmus routes, moreover, needed improvement. Capital must be induced to do the work, and one necessary inducement was a guarantee of stable conditions of investment.