Organization at the outset

In order to better understand the upcoming entries on officer assignments within the First (later Fourth) US Cavalry over the course of 1861, I will first examine the organization of cavalry companies and regiments before the war began.

These organizations are described in General Orders, No. 15, May 4, 1861, as part of President Lincoln’s call for volunteers. The organization of a company of cavalry at this time consisted of:

Captain (1)
1st Lieutenant (1)
2nd Lieutenant (1)
1st Sergeant (1)
Company Quartermaster Sergeant (1)
Sergeants (4)
Corporals (8)
Buglers (2)
Farriers and Blacksmiths (2)
Saddler (1)
Wagoner (1)
Privates (56-72)

As stated in a previous entry, two companies composed a squadron, with no further personnel assigned. Regular regiments at the outbreak of the war were each composed of five squadrons, or a total of ten companies. The personnel assigned to the regimental headquarters in each regiment consisted of:

Colonel (1)
Lieutenant Colonel (1)
Major (2)
Adjutant (1 lieutenant)
Regimental Quartermaster and Commisary (1 lieutenant)
Assistant Surgeon (1)
Sergeant Major (1)
Regimental Quartermaster Sergeant (1)
Regimental Commisary Sergeant (1)
Hospital Steward (1)
Chief Buglers (2)
Musicians for Band (16)

Maximum total strength for a ten company regiment at this time is 978 --- 34 officers and 944 noncommissioned officers and enlisted men. With the addition of two more companies to each regiment once the 6th US Cavalry was formed later in the year, a third major was authorized for each regiment. The regimental bands were later disbanded (no pun intended), but this is where the regiments stood if at full strength at the outbreak of the war.