1. Teeth Arm

Infantry Battalion
Bttn HQ: 1(5 man) rifle sqd
4 Companies@
CHQ: 1-2 rifle sqds
2 platoons@ 2-5(12 man) rifle sqds
Philippino Scout Battalion
Bttn HQ: 1(4 man) rifle sqd
4 Companies@
CHQ: 2(8 man) rifle sqds
2 platoons@ 5(9 man) rifle sqds

Divisional Cavalry Squadron

SHQ (Bttn HQ): 2 rifle sqds, horses
4 Troops@
THQ: 1(8 man) rifle sqd, horses, sbres, pistols
2 platoons@
1(6 man) rifle PHQ sqd
4(7-9 man) rifle sqds
horses, sabres, pistols

2. Regiment Support

Infantry Regiment HQ: 3 rifle sqds on horses, 3 rifle sqds with:
1 MG Company:
CHQ: 1(12 man) pistol sqd
2 platoons@ 2x Benet-Mercie LMG, pack mules, 20 men

Cavalry Regiment HQ: 5 rifle sqds with:

1 MG Troop: 4x M1904 Maxim MMG, 71 men, horses, pack horses

3. Divisional Support

Up to:
2-3 Infantry Brigade HQ@ 15 men, horses
2 Artillery Battalions@ BHQ: 2 rifle sqds, horses, Obsolete FC
3 batteries@ 4x 76mm M1903 field guns or 75mm Vickers M01 Mountain Guns, horses

1 or 3 Engineer Companies@
CHQ: 2 rifle sqds
2 platoons@ 2-5(12 man) rifle/engineer sqds

0-1 Signals Company: telephones

4. Notes

a) No radios at all.
b) The 4 Divisions should have 3 Brigades each of 3 Regiments each of 3 battalions, plus a Divisional Cavalry Regiment of 3 Squadrons. In practice there were only 3 divisions equipped, with 5, 6 and 10 Infantry Regiments respectively.
c) Divisional artillery should have 3 battalions of 76mm and a fourth battalion with 3.8" howitzers. In practice only two divisions had any at all, as shown.
d) In 1917 the MG units were increased to 6 guns.
e) The Philippino Scouts served in the Philippines, there being 12 battalions.
f) In 1917 there were 3 divisions on the Mexican border.