An army corps is 2 or more divisions, supplemented by cavalry, artillery, engineers, etc., under a major-general or lieutenant-general.
CAVALRY.
A section is 8 men under a corporal.
A platoon is 36 to 50 men under a lieutenant, or junior captain.
A troop is 3 to 4 platoons, 125 to 150 men, under a captain.
A squadron is 3 troops under a senior captain, or a major.
A regiment is 4 to 6 squadrons under a colonel.
A brigade is 3 regiments under a brigadier-general.
A division is 2 or 3 brigades under a major-general.