In all this series of fightings the main motives were self-defense, resistance to oppression, the enlargement of liberty, and the conservation of national acquisitions. The war with Mexico, it is true, was of a wholly different type. That was a war of conquest, and of conquest chiefly in the interest of African slavery. It was also an unjust attack made by a powerful people on a feeble one; but it lasted less than two years, and the number of men engaged in it was at no time large. Moreover, by the treaty which ended the war, the conquering nation agreed to pay the conquered eighteen million dollars in partial compensation for some of the territory wrested from it, instead of demanding a huge war-indemnity, as the European way is. Its results contradicted the anticipations both of those who advocated and of those who opposed it. It was one of the wrongs which prepared the way for the great rebellion; but its direct evils were of moderate extent, and it had no effect on the perennial conflict between individual liberty and public power. In the meantime, partly as the results of Indian fighting and the Mexican war, but chiefly through purchases and arbitrations, the American people had acquired a territory so extensive, so defended by oceans, gulfs, and great lakes, and so intersected by those great natural highways, navigable rivers, that it would obviously be impossible for any enemy to overrun or subdue it. The civilized nations of Europe, western Asia, and northern Africa have always been liable to hostile incursions from without. Over and over again barbarous hordes have overthrown established civilizations; and at this moment there is not a nation of Europe which does not feel obliged to maintain monstrous armaments for defense against its neighbors. The American people have long been exempt from such terrors, and are now absolutely free from this necessity of keeping in readiness to meet heavy assaults. The absence of a great standing army and of a large fleet has been a main characteristic of the United States, in contrast with the other civilized nations; this has been a great inducement to immigration, and a prime cause of the country's rapid increase in wealth. The United States have no formidable neighbor, except Great Britain in Canada. In April, 1817, by a convention made between Great Britain and the United States, without much public discussion or observation, these two powerful nations agreed that each should keep on the Great Lakes only a few police vessels of insignificant size and armament. This agreement was made but four years after Perry's naval victory on Lake Erie, and only three years after the burning of Washington by a British force. It was one of the first acts of Monroe's first administration, and it would be difficult to find in all history a more judicious or effectual agreement between two powerful neighbors. For eighty years this beneficent convention has helped to keep the peace. The European way