How Many Men In A Regiment

In 1899 there are:

25 Regiments of Infantry
10 Regiments of Cavalry
7 Regiments of Artillery

Each Infantry regiment has three battalions and each battalion has 4 companies.
Each Cavalry regiment has four squadrons and each squadron has 3 troops.

Historically, they were never at full strength.

The Army requested 12 companies per Infantry regiment and Congress authorized 8 manned and 2 unmanned.

On June 26, 1876 each infantry company averaged 60.4 officers, NCO's and men.  42.3 of these men are privates.

INFANTRY

Supposedly each Infantry company got a Captain, 1 1st Lieutenant and 1 2nd Lieutenant for officers.  1 1st Sergeant, 4 Sergeants, 4 Corporals and 91 men  There were also 2 Artificers and 1 Wagoner.
8 companies of manned (A through H) and 2 of unmanned (I and K there is no J company) totals 872.
Each Regiment gets 1 Colonel, 1 Lieutenant Colonel, 1 Major (each commands one battalion), 1 Adjutant, 1 Regimental Quartermaster for officers.  1 Sergeant Major, and 1 Quartermaster-Sergeant for NCO's plus 1 Chief Musician, 2 Principle Musicians, and 20 Musicians

902 total per regiment at "full strength".  1,090 when I and K companies are manned.

CAVALRY

The Cavalry got 12 troops per regiment but, again, two were unmanned and only 44 privates were authorized.

Each troop is supposed to have a Captain, 1 1st Lieutenant and 1 2nd Lieutenant for officers.  1 1st Sergeant, 5 Sergeants, 4 Corporals 2 Trumpteers, and 88 men  There were also 2 Farriers and Blacksmiths and 1 Wagoner.

10 troops of manned (A through I and K there is no J troop) and 2 of unmanned (L and M) totals 872.

Each Regiment gets 1 Colonel (in overall command), 1 Lieutenant Colonel, 3 Majors (one squadron each), 1 Adjutant, 1 Regimental Quartermaster for officers.  1 Sergeant Major, and 1 Quartermaster-Sergeant for NCO's plus 1 Chief Musician, 2 Principle Musicians, and 20 Musicians

 1,062 total per regiment at "full strength".  1,248 when L and M troops are manned.

ARTILLERY

A typical Artillery battery is supposed to get a Captain, 2 1st Lieutenants and 1 2nd Lieutenant for officers.  1 1st Sergeant, 4 Sergeants, 4 Corporals and 56  men  There were also 2 Artificers and 1 Wagoner.

10 batteries of manned (A through I and K there is no J battery) and 2 of unmanned (L and M) totals 746.

Each Regiment gets 1 Colonel, 1 Lieutenant Colonel, 1 Major, 1 Adjutant, 1 Regimental Quartermaster for officers.  1 Sergeant Major, and 1 Quartermaster-Sergeant for NCO's plus 1 Chief Musician, 2 Principle Musicians, and 20 Musicians

776 total per regiment at "full strength".  894 when I and K batteries are manned.  The actual size of an artillery battery depends on the actual type and number of guns per battery.