At the outbreak of the great Civil War
, the regular cavalry at the disposal of the Federal Government
consisted of the First and Second Regiments of Dragoons, one regiment of Mounted Rifles, and the First and Second Regiments of Cavalry.
Early in the year 1861, the Third Cavalry was added to the others, and soon after, all six regiments were designated as cavalry and numbered serially from one to six.
The old regiments had been composed of ten troops, subdivided into five squadrons of two troops each, but the organization of the Sixth Cavalry Regiment called for twelve troops.
In July, 1861, this organization was extended to all regular regiments, and in September of the same year the volunteer regiments, which had started out with ten troops each, were organized in a like manner.
As the war progressed, the squadron organization was abandoned.
When a regiment was subdivided for detached service, it was usually into battalions of four troops each.
The early war organization of cavalry troops called for one hundred enlisted men to a troop, officered by a captain, a first lieutenant, a second lieutenant, and a supernumerary second lieutenant.
But in 1863, troops were given an elastic strength, varying between eighty-two and one hundred enlisted men, and the supernumerary lieutenant was dropped.
Each regiment, commanded by a colonel, had a lieutenant-colonel and three majors, with a regimental commissioned and