Its there... its just somewhat different and more a version of order arms. where the muzzle of the musket is a few inches from the shoulder and the stock only a few inches off the ground.
"Trail ARMS.
One time and two motions.
206. The same as the motion of order
arms, No. 154, by seizing the piece briskly with
the left hand a little above the middle band, and
detaching it slightly from the shoulder with the
right hand : loosening the grasp of the right hand,
lowering the piece with the left, reseizing the
piece with the right hand just above the lower
band, the little finger in the rear of the barrel, the
butt about four inches from the ground, the right
hand supported against the hip, dropping the left hand by the
side.
207. (Second motion.) Incline the muzzle slightly to
the front, the butt to the rear and about four inches from the
ground. The right hand supported at the hip, will so hold the
piece that the rear-rank men may not touch with their bayonets
the men in the front-rank."
View attachment 411160
(this is from Caseys,. but the text is the same in the other drill books)
It is used if marching under low hanging branches or similar. And also as an alternative to right shoulder shift arms, when moving quickly. Again if trees is an issue.
The 95th version is used when marching from A to B outside the battlefield.
(the danish manual of arms, have it exactly like the US version... but also one that is similar to the british... expressly for "roadmarching")
US drill.
From 1814 and until WWII the American military looked to France for its main inspiration.
By 1860 there where two drill books in use by the regular army.
One for heavy infantry by Scott. A word for word translation of the French 1835 drill. (and that one was just a slightly updated version of the one used by French infantry during the revolutionary and Napoleonic wars)
In 1855 the US army got "Hardee's" It again a word for word translation. This time of the French 1845 drill.
Faster movements, few stops in the evolutions and the orders use fewer words. And suppose to be used by light infantry and riflemen.
This is the core text that is used by pretty much everyone during the war.
Hardee revise his manual of arms, and Casey change a few details but 95% of the movements are the exact same as the French drill.
(A book the French btw no longer used )
And there where a number of other books, but they all plagiarized this translation... (legally, since his 1855 drill book was public domain)
For more on this I can suggest this article:
https://www.academia.edu/5532100/A_..._on_the_U_S_Army_from_1812_to_the_Mexican_War
The core of the tactical system is about moving in column And all movements should be covered by a skirmish screen.
This screen together with artillery should weaken the enemy, so when your column go forward the enemy is too week to stop you, so he get out of the way instead of trying to take the fight. If he do not fall back, you should get into line just outside of effective musket range and then move into range and take the firefight.
But in a perfect attack, you never go into line, until you have taken your objective that you then want to defend.
This should be very similar to what you might have read about how the French defeated the Prussians, Austrians or Russians.
(what often goes wrong against the British is that they for different reason get into effective range... take very effective fire and then try to go into line under fire. One issue being that British skirmishers effective countered the French skirmishers)
But it is not how civil war armies did things.
They generally only learned the basics and moved around in line by the flank. And when attacking the entire attack was done in line... and with few skirmishers. This was a lot simpler to learn and I would argue, less risky.
You could move forward into range and then take the firefight.
But This often resulted in a long firefight instead of the quick results of a column going forward.
(where if successful you quickly get the enemy falling back... or your attack gets stopped and you fall back out of range to reform.. again something that don't take a lot of time)
Also add the fact that most men did not have the skills to take advantage of their rifled weapons. This all combined so many attacks just resulted in heavy casualties for both sides. With no real result.
European drill.
By 1861 a change was happening. A number of armies (including the UK, Prussia and Denmark) had changed to having a heavy skirmish line as the main formation for fighting. And they wanted firepower to be the deciding weapon.
As an example is the danish "kjæde" it have about 2.3 times more men in the firing line pr. distance, compared to a American skirmish line..
The Austrians on the other hand still focused on the bayonet. But its important to remember that their attack columns was to be covered by 1/3 of the regiment skirmishing in front of the attack. Something that worked ok in their few engagements against Danes in 1864. (but not against Prussians with breech loaded rifles in 1866)
(The Danish army did not have the money to do a extensive marksmanship training program like the british, and not ensure the same level of training as the prussians. So plenty of danish units in 1864 did do close ordered counterattacks against the Prussians and got shot to pierces... but generally could fight the Austrians on equal level)
For a book on the rifle musket and how it influenced tactics outside of the US... and how it did not have any real infleunce on tactics during the the civil war I can suggest the book "The Destroying Angel" by Brett Gibbons. He is a serving Us army ordonnance officer who really know his guns and cartridges.
https://www.amazon.com/dp/B07GRG7ZJY/?tag=civilwartalkc-20
Its like 12USD in paperback.
sorry it sort of became very long...