The aggregate _militia_ force of the United States (including seceded portions), according to the last returns, was 3,214,769. The reports of the last census increase this to about 5,600,000, which exceeds to some extent the number actually _fit_ to bear arms. The computed proportion in Europe of the number of men who can be called into the field is about one-fifth or one-sixth of the population. If the population of the entire United States be assumed to be 23,000,000, the number of men liable, according to this computation, would be about 4,000,000, which is sufficiently approximate. The European computation of the force to be kept as a _standing army_ is a hundredth part of the population--varied somewhat by circumstances. This would give the United States a force of 230,000. It will be seen how greatly inferior our regular force has been and still is to the computations adopted in Europe. But the United States will probably never require such a large force to be permanently organized; for we have not, like the European powers, frontiers to protect against nations with whom we may at any time be at war, nor oppressed nationalities to retain in subjugation by force. Our frontiers on Canada and Mexico have good natural defences--the first by the St. Lawrence river and lakes, and the second by the great distance to be traversed by an invading army before it could reach any important commercial position. Our vulnerability is in our extensive seacoast. The principal requirement for an army is a large framework, which can be rapidly filled by volunteers in expectation of war. With such a military constitution and a system of military education and drill in the different States, large and effective armies could be rapidly organized. Our staff corps and regular army are insignificant, compared with those of European nations, in which the average strength of the standing armies is from 250,000 to 300,000 men on the peace footing, and 400,000 to 600,000 on the war footing, with immense magazines of equipage and material, numerous military schools, and extensive organizations in all the departments incident to an army. Our own army has hitherto been modelled to a great extent on the English system--the most aristocratic of all in Europe, and consequently the least adapted to a republic. To this is attributable much of the jealousy hitherto felt in regard to the army and all pertaining to it. We are now, however, conforming more to the French system, and from it will probably be adopted any changes that may be introduced.