It is a matter of semantics.
As Van Dorn's Army [including the Missouri State Guard-MSG] headed east to cross the Mississippi River after the battle of Pea Ridge, much of the MSG continued its transition from state troops to Confederate troops. After General Price transferred from the MSG to Confederate service, the remainder of the State Guard came under the command of State Guard General Parsons.
This was variously referred to as command, brigade, state forces, MSG, etc. And it did indeed cross the Mississippi River and went on to Corinth as a distinct element of Van Dorn's army.
Examples of the different descriptions of Parson's command can be found in NARA, RG 109 and other sources as indicated: [The dates are all 1862]
5/13 Camp Churchill Clark S O #14
II-The reserve Btrys will be under the immediate command of Col J P Major and composed of Landis, Clark’s Btry under King. They will take position at these Hqs.
III- Capt Barrett will report his Btry to Gen Bragg
IV-Capt’s Baker, Gorham & Bryant will report their Btrys to Maj Shoup inspector of Arty
5/18 Arty Bgde, Camp Churchill Clark, Col M L Clark issues S O #19-The Arty Co’s of Gorham, Guibor & Kneisley will be reorganized into 2 full Co’s with 4 guns each. ..The Co now known as Capt Gorham’s will be attached to Parsons’ Brigade and the Capt of the other Co will report to Gen Green. Col Major is charged with the execution of this order.
5/21 Corinth HQ Gen Price Div-recommends the immediate appt of Parsons & Green as B Gen'ls with orders to report for duty with this Div.
5/26 Gen Parsons came down [Priest was guarding bridge 10 Mi S of Corinth] today with his entire command. Camp Fire & Prison Journal
5/29 Parsons' Infy moved to Tupelo. Gen Parsons commanded the Mo Div while Gen Price was in Richmond conferring with President Davis
6/18 S O #117 Priceville
6/19 Breckenridge's reserve corps was increased by a Brigade of Missouri Infy under Gen Parsons ___all of them detached from the army and marched to Pontotoc—Tallahatchie bridge for Miss Central RR-Command under Preston
7/13-Spec Orders HQ Dept, No. 2, No. 115 Tupelo
4/8/62 Des Arc-G O #26 MSG
I. Brig. Gen M. M. Parsons is hereby specially detailed to the command of all the MSG now in the field, and will immediately organize them into Co’s, Bns, and Regts, according to law.
II. The army corps to be thus organized will consist exclusively of infantry and Arty.
III. The general cdg will report as soon as practicable the entire force in the MSG now remaining, rank and file.
By order of the Governor: Warwick Hough, Adjutant-Gen of Missouri
I-The assignment of Btrys to the several Bgdes of the Army of the West-under Par VII S O #83 of 5/12 will be as follows:
Price’s Div:
Little’s Bgde-Wade’s Btry
Whitfield’s Bgde-McDonald’s Btry
Green’s Bgde-Kneisley’s Btry
Parsons’ Bgde-Guibor’s Btry
S Jones Div:
Rust’s Bgde-Lucas’ Btry
Maury’s Bgde-Bledsoe’s Btry
Roane’s Bgde-Gaines’ Btry
McCown’s Div:
Cabell’s Bgde-Goode’s Btry
Churchill’s Btry-Provence’s Btry
By order of Col M L Clark cdg Arty Bgde
Price's letter of 5/21 says he has rec'd communication addressed to Gen Slack by M J Grinstead to notify him the president had apptd him a B Gen in the PACS
As also a similar communication addressed to Col P A Rives to inform him of his appt as Col
These came too late to be forwarded to the gallant officers to whom they were addressed. They had both died in battle long before the letters reached these HQ
calls to Sec of War's attention of telegram I sent him from Memphis on 4/21 to request the Pres to appoint one or more B Gen'ls --no regard seems to have been paid to that dispatch
Over 8000 Missourians have been mustered into the CSA service.
Van Dorn endorsement-it will be seen by the report of Gen Price’s Div that Gen Little & Gen Green command all the Missourians in....Confederate service. I recommend Gen Green therefore but not Gen Parsons until there is a Brigade for him to command
II. The troops under the command of Gen M. M. Parsons, known as the Mo State Guard, are relieved from duty with this army & will prepare to march tomorrow with 8 days' rations. The Confederate troops under Gen Parsons will, if Arty, report to the cdg officer of the Arty Bgde; if Infy or Cav, will report to the cdg officer of their division (Gen Little). A Btry of 4 pieces of Arty will march with him. The rest of the Arty of Parsons' Brigade will be turned over to the chief of Arty or such officers as he may order to receive it, who will give the necessary receipts for the same. Gen Parsons will cause descriptive lists to be furnished to the Confederate troops under his command
History of the Orphan Bgde by Thompson
I. The MSG, under command of Brig Gen M. M. Parsons, are relieved from further service east of the Ms River, and will proceed with the least practicable delay to join the forces of Major-Gen Hindman as soon as practicable. The general cdg desires to express to Gen Parsons and his gallant officers and men his high appreciation of their patriotic devotion to the cause in which we are engaged, which has ever distinguished the citizens of Missouri in the armies of the CS.
II the QM’s dept will furnish the necessary means of transportation to facilitate the earliest possible execution of this order. By command of Gen Bragg: Official Records
After returning west of the Mississippi, Parsons continued to be variously termed as command, Brigade, etc.
His Confederate brigade was formed after his MSG troops converted to Confederate troops in Arkansas and was reinforced when he arrived at Yellville.
10/3/62 to M. M. Parsons en route to Yellville
After camping a short time at Ark Post, Gen Parsons started north for the purpose of recruiting his Bgde. We went as far north as Yellville. There we received a large number of recruits
James L. Grubbs
10th Missouri Inf Regt
Parsons' Division
10/10 camp at Yellville HQ Parsons’ Brigade-no recruits recruited by authority of Col Waldo Johnson have yet arrived. I recd a letter yesterday from Col Weldon one of my aids who was authorized to recruit Inf in Oregon and adjoining counties- He informs me that Col Burbridge or his partisan ranger Regt has 250 men, that Col Mitchell for his Regt of cavalry has 600 men. Alexander Papers
10/22 Shaver joins Parsons at Yellville-
10/23 Gen Parsons' hdqrs. Yellville to Hindman-A part of Steen’s and Shaver’s Bgdes [so now still 2 separate Bgdes?] arrived yesterday giving me a force of 3000 but only about 2000 arms.... we are now issuing them the balance of arms, etc., brought by me across the Ms River..Although no formal report has been made of the arms and clothing of these men, I observed their deficiencies by moving among them. I distributed to them all I had left of what I brought across the river with me and I will form a train to Little Rock for arms, ammo and camp equipment. I have temporarily attached the Infy of my former command [which could only be Priest and Winston’s commands now probably referred to loosely as separate Bns] to Col Steen’s Bgde and ordered him and his Bgde to the vicinity of Bellefonte in Carroll County immediately after the distribution of what arms and ammo I have. Your instructions of the 20th were rec’d last evening and the accompanying order to Col Burbridge sent to him at once. Alexander Papers
11/9 -order #38 Hqs Dist of Ark-camp on Mulberry-announcing organization of 1st corps Trans Miss Army
2nd Bgde-Col Shaver
General officers in MSG will have the same relative rank in Confederate Army.
For unity of command, the troops ordered to Yellville and those under Gen Rains will constitute one command under the senior officer.
A more perfect organization will be effected as soon as Hindman can go there in person. Should the command devolve on you by rank-you are to get from Raines copies of the letters of instruction, all orders, etc.
If practical the force ordered to Yellville will take position nearer Elk Horn and further north than Yellville Alexander Papers
THE LAST COMPANY THAT SURRENDERED
Parson's and Shaver's Bgdes.... had united at Yellville before marching south to Hindman’s camp. Col Shaver broke camp on 10/11 and moved west to Smithville on 10/13. On 10/15, he reached Evening Shade and after 11 days finally reported to Parsons at Yellville 10/22. Parsons was expecting 4000 Infy with Shaver, but he had only 3000 including 1000 unarmed and all destitute of supplies and equipment.
Embattled Arkansas by Banasik
Third division-Gen Parsons
1st Bgde-Col Steen
1. Steen Regt Missouri Inf
2. Hunter “
3. Caldwell “
4. White “
Tilden Missouri btry
1. Shaver Regt Ark Inf
2. Shaler “
3. Grinstead “
4. Adams “
Roberts Missouri btry
Unattached-Roberts’ co Missouri cavalry
Alexander Papers
11/17 Gen Frost assumes command of Parsons' division [Parsons assumed command of Steen's Brigade]
Serving with Honor