Vaulting & Mounting.
From Congdon's Cavalry Compendium ~ 1864 and Poinsett's Cavalry tactics ~ 1841

Manner of Vaulting.

Seize the mane with the left hand, hold the reins in the right hand, and place it on the withers, the thumb to the left, the fingers to the right; raise yourself lightly on the two wrists, the body straight; pass the right leg extended, over the croup of the horse, without touching him, and seat yourself gently on his back.

To Dismount. — Pass the left rein into the right hand; place this hand on the withers seize the mane with the left hand, raise yourself gently on the two wrists; pass the right leg extended, over the croup of the horse, without touching him; bring the right thigh near the left, the body straight, and come to the ground lightly on the toes, bending the knees a little.


Mounting.

Position of the Trooper Before Mounting.

The trooper places himself on the left side of the horse, abreast of the nether jaw; he holds the reins with the right hand, at six inches from the mouth of the horse, the nails downward, the rest of the body in the position of the trooper dismounted. When the trooper is under arms, he has the left hand over the sabre.

To Mount when Formed in Two Ranks.
At open order, the command is:
Prepare to MOUNT.
One time, two motions.
1. At the command, PREPARE TO MOUNT, Nos. 1 and 3 of each rank move six paces to the front, stepping off with the left foot, keeping opposite their intervals, and regulating by the right.
Place the carbine over the shoulder Place the right foot three inches in rear of the left; make a face and a half to the right on both heels, the right foot remaining in front; let go the right rein, slip the left hand along the left rein, take two steps, stepping off with the right foot, face to the left upon the point of the left foot, the right side towards the flank of the horse; carry back the right heel three inches in rear of the left; the right hand, seizing the end of the reins, is placed upon the cantle of the saddle.
2. Place a third of the left foot in the stirrup, supporting it against the forearm of the horse; rest upon the point of the right foot, and seize with the left hand, over the reins, a lock of mane as far forward as possible, the extremity of the lock passing out of the hand on the other side of the finger.

MOUNT.
One time, two motions.
1. At the command MOUNT, spring from the right foot, holding firmly to the mane, at the same time pressing upon the cantle to prevent the saddle from turning; the body erect.
2. Pass the right leg stretched over the croup of the horse, without touching him; sit lightly in the saddle, placing at the same time the right hand, without quitting the reins, upon the right holster,
the palm of the hand resting upon it, the fingers on the outside of it; pass the reins of the bridle into the left hand, and adjust them; place the right foot in the stirrup.

Form Ranks.
At the last part of the command, which is RANKS, Nos. 1 and 3 raise the wrist of the left hand, and hold the legs close to the body of the horse to keep him quiet; Nos. 2 and 4 enter the intervals without jostling and without precipitation.
The rear rank being formed, closes to the distance of two feet from the front.

POSITION OF THE TROOPER MOUNTED.
The buttocks bearing equally upon the saddle, and as far forward as possible;
The thighs turned upon their flat side without effort, embracing equally the horse, and stretched only by their own weight and that of the legs;
A supple bend of the knees;
The legs free and falling naturally;
The point of the feet falling in like manner;
The loins supported without stiffness;
The upper part of the body at ease, free and erect;
The shoulders equally thrown back;
The arms free, the elbows falling naturally;
The head erect, at ease, and not drawn in between the shoulders;
The reins in the left hand.

Position of the Bridle-Hand.
The reins in the left hand, the little finger between the reins, the other fingers well closed, and the thumb upon the second joint of the first finger; the elbow slightly detached from the body, the hand four inches above the pommel of the saddle, the fingers six inches from and turned towards the body; the little finger a little nearer the body than the upper part of the wrist, the right hand at the side; bear very lightly on the bit.


Dismounting.

1. Prepare to DISMOUNT.
One time, two motions.
At the command Prepare to DISMOUNT, Nos. 1 and 3 of the front rank move forward six paces. Nos. 2 and 4 of the rear rank rein back four paces, and keep themselves opposite their intervals. The troopers of each rank dress by the right.
Pass the right rein into the left hand, the extremity of the reins leaving the hand on the inside of the thumb.
Seize the carbine with the right hand at the sight; pass it over the right shoulder diagonally, the muzzle in the air, so that it cannot fall back.
Seize the reins above and near the left thumb with the right hand, the nails downward; place this hand on the right of the pommel. Disengage the right foot from the stirrup, and seize with the left hand a lock of mane over the reins.

2. DISMOUNT.
One time, two motions.
1. At the command DISMOUNT, rise upon the left stirrup; pass the right leg extended over the croup of the horse, without touching him, and bring the right thigh hear to the left, the body being well sustained; place at the same time the right hand on the cantle of the saddle, slipping it along the reins without letting them go; descend lightly to the ground, the body erect, the heels upon the same line. Let go the mane with the left hand; engage the extremity of the reins in the left cloak strap with the right hand, which then seizes the left rein.
2. Make a face and two steps to the left, stepping off with the left foot; slip the right hand along the left rein, seize with the same hand both reins six inches from the mouth of the horse, the nails downward, and take the position before mounting.

Form—RANKS.
At the last part of the command, which is RANKS, Nos. 1 and 3 of each rank elevate slightly the right hand to keep the horse quiet; Nos. 2 and 4 return to their intervals gently.