C Company was organized on 1 September
1846, with Captain Samuel H. Walker as its commander. 

He is listed as being "…on detached service at Washington, obtaining equipment and recruits for Company…" until 21 May, 1847.  No doubt the "equipment" he was obtaining was the
shipment of 1000 Colt-Walker revolvers
he had co-designed with Samuel Colt.  Walker continued in command until September, when
he was placed in arrest for unspecified reasons.
Released after a month, he took command of a
battalion of Cavalry, only to die on 9 October in
the battle at Huamantla.

Vera Cruz, Mexico 10 March, 1847 - C Company Leads General Scott's Investment of
the City

C company captures a Mexican mule train loaded with kegs of wine.  Dabney Maury, 2LT, Co.
 C wrote:

"When our work for that day was done…We were very hungry and

thirsty. So our Texas guide lassoed a fat beef, a keg of sherry was

broached, and we bivouacked upon the northern beach of Vera Cruz,

just beyond the cannon range of the city, and remained there until,

after two or three weeks bombardment, Vera Cruz surrendered."

Fortress of San Juan de Ulloa 23 March, 1847 - Companies C & D defeat the enemy at Puente
Del Medio.

 "Chapultepec castle was taken by a pair of hand-picked, 250-man storming parties, which included Mounted Riflemen under the command of Captain Benjamin S. Roberts, who would later command Company C. Seeing a party of Marines falter during the assault after losing most of their officers, Lieutenant Robert M. Morris of the Mounted Rifles took charge and led them on to victory. During
the assault, other elements of the Regiment captured an enemy artillery battery at the foot of the
castle. 

    After these actions the Regiment was immediately reformed and advanced down the Tacubaya Causeway to storm the Belen Gate which barred the way into Mexico City.  The hard-fighting
Riflemen captured another artillery battery halfway to the gate at Casa Colorado, and a third during
 the assault on the gate.  

    Leading the American forces, the Regiment stormed into Mexico City at 1:20 that afternoon. 
At 7:00 A.M. on 14 September 1847, Sergeant James Manly of F Company and Captain Benjamin
S. Roberts raised the American Flag over the Mexican National Palace while Captain Porter,
Commander of F Company, unfurled the Regimental standard from the balcony. 

    As recalled by Major General John A. Quitman, “When forming my division on the plaza, I
perceived several non-commissioned officers hastening towards the palace with their regimental
 colors. I cried out, ‘No, my brave fellows, take back your colors. The first flag on that palace must
be the flag of our country.’ Captain Roberts, of the Rifles, was then directed to bring forward a
stand of National Colors and plant them upon the palace.”

Captain Benjamin S. Roberts’ letter to General D. E. Twiggs:

                                                      City of  Mexico, Sept 17, 1847.

Sir:

   I have the honor to return the American Flag you entrusted to my keeping in the storming of Chapultepec, and the taking of the City of Mexico.  Your charge to me was, “I expect that Flag to be the first placed upon the Capital of Mexico.”  The Commission has been executed and the first
American Flag that ever floated upon the Palace of the Capitol of Mexico is now returned to you.

   It was also the first planted on the 5 gun battery stormed and carried by my assaulting party at the left of the enemy’s line at Chapultepec.

   It was also the first planted on the battery stormed and carried by the Rifle Regiment between Chapultepec and the Gareta.

   It was also the first planted on the batteries at the Gareta and the first on the Citadel of the city.

   It was carried by Sergeant Manley of “F” Co., whom I selected to bear so distinguished a flag, and the anticipations I entertained of his doing honor to the banner of his Country were not disappointed. I desire to commend him to your special consideration. This Flag would have been returned through him
but for a severe wound that confined him to his Quarters….. On inspection you will perceive that the Flag has been pierced six times by the balls of the enemy.

                   I have the honor to be with high regards, etc.

                                                                     (Signed) B. S. Roberts,

                                                                                            Capt. Rifles.

Gen. D. E. Twiggs,

                Commanding, 2d Division.

“The United States Army counted September 14, 1847, one of the most glorious days in its
half-century of history. It opened as General John A. Quitman led the Fourth Division of Winfield
Scott’s army through the narrow streets of Mexico City. In the spacious Plaza de Armas, bordered
by the twin-spired cathedral and the looming National Palace recently vacated by Santa Ana, a conquered populace watched silently as the begrimed citizen-soldiers from the north formed in
line facing the seat of government. Captain Benjamin S. Roberts of the Mounted Rifles climbed to
the roof and as the division p-resented arms hoisted the American flag on the staff surmounting the dome.”
 – Robert M. Utley, “FRONTIERSMEN IN BLUE The United States Army and the Indian,
1848-1865.

    Washington City, District of Columbia 9 June 1847 - Christopher "Kit" Carson appointed as 2LT,
 RMR by President Polk. Assigned to Company C.

    Due to his involvement with John Charles Fremont (also a member of the Rifles) during the
California Bear Flag Revolt, the US Senate refused to confirm his appointment.  He is carried on
the rolls of Company C from May through December, 1847 as " Not joined since appointment". 

    For action at Hay Creek, near Deadwood, on 23 February 1877, Troop C is entitled to the following campaign participation credit: "South Dakota 1877."  
    
    Private Allen Walker was awarded the Medal of Honor for gallantry in action in Texas, 30
'December 1891:

 Rank and organization: Private, Company C, 3d U.S. Cavalry. Place and date: Texas, 30 December
1891. Entered service at:------. Birth: Patriot, Ind. Date of issue: 25 April 1892. Citation: While
 carrying dispatches, he attacked a party of 3 armed men and secured papers valuable to the United States."

FROM WYOMING STATE PARTS WEBSITE:

"In accordance with the Treaty of 1868, Forts Reno, Phil Kearny, and C.F. Smith, along the Bozeman Trail were abandoned. Fort Fetterman, alone, remained on the fringe of the disputed area. As an
outpost of civilization on the Western frontier, the fort represented protection and a haven to
travelers. Fort Fetterman was always considered a hardship post by officers and men who were
stationed there. On May 18, 1874, Captain F. Van Vliet, of Company C, 3rd Cavalry, felt so strongly
about the hardships on his men that he wrote to the Adjutant General requesting his company be transferred because there was "...no opportunity for procuring fresh vegetables, and
gardens are a failure. There is no female society for enlisted men...the enlisted men of the company
are leaving very much dissatisfied, as they look upon being held so long at this post as an unmerited punishment...whenever men get to the railroad there are some desertions caused by dread of
returning to this post..."

BATTLE OF CERRO GORDO, MEXICO

APRIL 18, 1847

SECOND DIVISION - GENERAL. TWIGGS

Colonel Harney's First Brigade
Mounted Rifles
 
Wounded:
21. 2d Lt. George McLane, Co. C, dangerously, April 18.
22. 2d Lt. Dabney H. Maury, Co. C, severely, April 17.
23. Sgt. Thomas Sloan, Co. C, slightly, April 17.
24. Cpl. Thomas Goslin, Co. C, April 17.
25. Pvt. George W. Gillespie, Co. C, slightly, April 17.
26. Pvt. John Raney, Co. C, slightly, April 17.
27. Pvt. Joseph Windle, Co. C, severely, April 17.
28. Pvt. Her. Zimmerman, Co. C, severely, April 17.
29. Pvt. James McGowan, Co. C, slightly, April 18.
 
BATTLE OF EL MOLINO DEL REY, MEXICO
SEPTEMBER 8, 1847
 
HARNEY’S BRIGADE
 
Mounted Rifles
Wounded:
1. Sgt. McGuire, Co. C, slightly.
2. Cpl. Slade, Co. C, slightly.
 
Sources: 30th Congress. 1st Session. Executive Document No. 8: Message from the 
President of the United States...(Washington, D. C.: 1848?), pp. 447-456
Daily American Star, Mexico City, Mexico, Vol. 1, No. 36, November 11, 1847, pp. 1
Niles' National Register, Baltimore, Maryland, Oct. 30, 1847, pp.142-143
Anonymous. Complete History of the Late Mexican War (New York: F. J. Dow & Co., 1850), 
pp.114-119
Steven R. Butler. A Complete Roster of Mexican War Officers, Both Army and Navy
 (Richardson, Texas: 
Descendants of Mexican War Veterans, 1994).
 
 
AFFAIR AT HUAMANTLA, MEXICO, OCTOBER 8, 1847
AND SUBSEQUENT ACTION, OCTOBER 1O & 11, 1847
 
Killed:
1. Capt. Samuel H. Walker, Co. C, U.S. Mounted Rifles.
2. Cpl. Joseph E. Merriken. Co. C, U.S. Mounted Rifles.
3. Pvt. Hergenin or Hugenen, Co. C, U.S. Mounted Rifles.
4. Pvt. Tarbox, Co. C, U.S. Mounted Rifles.
8. David, a negro slave, servant to Captain Walker.
10. Pvt. Meachem, Co. C, U.S. Mounted Rifles; severely.
11. Pvt. Raborg, Co. C, U.S. Mounted Rifles; lost a leg.
12. Pvt. Welch, Co. C, U.S. Mounted Rifles; slightly.
13. Pvt. Wayne, Co. C, U.S. Mounted Rifles; slightly.
14. Pvt. McGill, Co. C, U.S. Mounted Rifles; slightly.
15. Pvt. Scott, Co. C, U.S. Mounted Rifles; slightly.
16. Pvt. Myers, Co. C, U.S. Mounted Rifles; slightly.
 
Missing:
1. Sgt. Goslin or Gosling, Co. C, U.S. Mounted Rifles.
2. Pvt. Dement, Co. C, U.S. Mounted Rifles.
3. Pvt. Isaac P. Darlington, Co. C, U.S. Mounted Rifles.
4. Pvt. Collins, Co. C, U. S. Mounted Rifles.
5. Pvt. McCleary or McCleerey, Co. C, U.S. Mounted Rifles.
6. Pvt. Richards, Co. C, U.S. Mounted Rifles.
 
Source: Niles’ National Register, Baltimore, Maryland, November 27, 1847, p. 195
Albert G. Brackett. General Lane’s Brigade in Central Mexico 
(Cincinnati: H. W. Derby & Co., 1854), 
p. 331-332.
 
These I found listed as missing but I don't know in which battle(s).
NAME                                                                RANK         COMPANY
 
Collins                                                                 Private                   C
Isaac P. Darlington                                           Private                   C
Dement                                                              Private                   C
Goslin or Gosling                                              Sergeant                 C
McCleary or McCleerey                                  Private                   C
Richards                                                            Private                   C
 
Battles from list in 1933 history of the regiment by RCHAP:
 
Mexican War:
 
20 Jun 1847                           Pass of La Hova, Mexico                              C
19 Oct 1847                            Atlixco, Mexico                                              C
 
Civil War:                                
 
21 Feb 1862                            Val Verde, NM                                    C, D, G, I and K
  3 Mar 1862                           Comanche Canyon, NM                     C and Detachment K
26-28 Mar 1862   Apache Canyon, NM, (Glorieta or Pigeon Ranch)            C and E
15 Apr 1862                            Peralta, NM                                         C, D, E, G, I, and K
18 Jun 1862                            Canyon Ladrone, NM                         Detachment C
21 Oct 1863                            Cherokee Station, AL                         C, F, G, and I
26-27 Oct 1863                      Tuscumbia, AL                                    B, C, F, G, I, and K
  5 Sep 1864                            Near Benton, AR                                 B, C, F, G, I, and K
22 Jan 1865                            Near Little Rock, AR                          Detachment B, C, F and I
Indian Wars:
 
30 Nov 1856                           Near Sacramento Mountains, NM       Detachment C
24 May 1857 Mogollon Mountains (El Canyon de los Muertos Carneros) NM  C, D, and I
2 Oct 1858                              Laguna Chusca, near Ft. Defiance, NM         A and C
8 Feb 1859      Dog Canyon, (Sacramento Mountains), NM                Detachment C
12-26 Nov 1859                      Pinal Apache Expedition, NM               Detachments C and H
15 Jul 1860 Canada de los Penavetitos, NM (Canadian River Expedition) A, C, D, F, H, and K
18 Jun 1861                             Penasco River, NM                                 Detachment C
25 Dec 1868 Wichita Mountains North Fork of Red River, Indian Territory A, C, D, F, G, and I
24 Jun 1870                             White Mountains, AZ                           Detachments A, C, L, and M
9 Jun 1876                               Tongue River, WY                  A, B, C, D, E,             F, G, I, L, and M
17 Jun 1876                             Rosebud River, MT                A, B, C, D, E,             F, G, I, L, and M
9 Sep 1876 Slim Buttes (surprise of American Horse), Dakota A, B, C, D, E, F, G, I, L, and M
23 Feb 1877                            Hay Creek, near Deadwood, Dakota             C
21-22 Dec 1891                      Retamal, TX                                                Detachment C
24 Jan 1892                             Rancho, Grominito, TX                             Detachment C and K
6-15 Feb 1892                         Near Grande, TX                                       Detachment C
 
 
Philippine-American War:
12 Nov 1899                           Asingan, Pangasinan, PI                                 A and C
17 Nov 1899                           Near San Nicolas, Pangasinan, PI                  C, E, and L
12 Jan 1900                            Near Segupin, Union, PI                                C
19 Jan 1900                            Palasi Pasa, Union, PI                                    C
  Mar 1900                              San Francisco, Union, PI                               C
  6 Apr 1900                           Near Balaoang, Union, PI                               C
 
Spanish-American War:
 
22 Jun 1898                             Santiago, Cuba (siege and surrender of,       B, C, E, F, G,
                                                embracing the action San Juan Hill, July        H, I, and K
                                                1-3 and around Santiago July 3-17
 
Mexican Border Service:
 
            
1912                                        Skirmishes along Mexican Border                  A,B,C