By law of August, 1789, a department of war, and in 1798, a secretary of the navy is provided to aid the President in the administration of military and naval affairs; and the original rules and articles of war enacted by the Congress of 1776, were continued in force, and in 1806 made the basis of the military code which has since governed all troops mustered into the service of the United States.
In 1790 the rank and file of the regular army was fixed at 1,216 men. In 1796 this force was organized into one corps of artillerists and engineers, whose head-quarters was at West Point, two companies of light dragoons, and four regiments of infantry of eight companies each. This force was increased by additional regiments in the war of 1812, the Indian war in Florida, and the war with Mexico, till in 1861, the army consisted of 14,000 men, stationed in the different forts and garrisons, and mainly on the Indian frontier. In the war of the Rebellion the regular army was increased to 50,000 men.
By act of July 15,1870, the number of enlisted men was reduced to 30,000 by or before July 1, 1871. On the 20th of October, 1871, the army was composed as follows:
| Two regiments of Cavalry, | 8,800 | enlisted men. |
| Five regiments of Artillery, | 3,105 | “ “ |
| Twenty-five regiments of Infantry, | 23,742 | “ “ |
| One battalion of Engineers, | 314 | “ “ |
| Ordnance Department, | 444 | “ “ |
| West Point Detachment, | 202 | “ “ |
| Signal Department, | 199 | “ “ |
| Hospital stewards, | 310 | “ “ |
| Ordnance Surgeons, | 114 | “ “ |
| Available Recruits, en route, | 349 | “ “ |
| Permanent Recruiting Parties, | 904 | “ “ |
| General Service Men, | 420 | “ “ |
| Total, | 29,003 | |
| Commissioned Officers, | 2,105 | |
| Retired Officers, | 295 |
When the insurrectionary movements and combinations of the Southern States in 1861, proved too powerful to be suppressed by ordinary civil powers, the President, April 15, called for 75,000 volunteers for three months, to defend the capital, and May 3, 42,000 to serve for three years or during the war. On the 22d of July he was authorized to accept the services of 500,000, which, within six months afterwards was increased to 1,000,000. This force proving inadequate, a levy of 300,000 men was ordered in 1863, and in 1864, another call for 500,000 men—making an aggregate of 2,653,062 mustered into the service of the United States, or nearly one fourth of the entire male population of the Northern States. This entire force was disbanded within one year from the close of the war.
The development of the naval resources of the country was quite as marvelous. In 1861 the entire navy consisted of 94 war vessels of all classes and in all conditions, capable when in service of carrying 2,415 guns. Only 43 of these ships were in commission, and the seamen and mariners numbered 7,000. In less than three years 200 war vessels were constructed and 418 merchant vessels were converted to military service, and over 50,000 men enlisted in the naval service.
The Southern States in rebellion put into the field over 500,000 men, and exhausted their pecuniary resources, with the loss of 300,000 soldiers on the field or in hospital.
The debt of the United States contracted in the prosecution of the war, stood in 1866 at the enormous sum of $2,783,425,879.
These extraordinary efforts were made under circumstances which are not likely to exist again, and such expenditures could not be repeated without national bankruptcy.