FIFTH REGIMENT.
| First Battalion. | Second Battalion. | Third Battalion. |
| 17th (A) Company. | 18th (E) Company. | 16th (I) Company. |
| 49th (B) Company. | 43d (F) Company. | 20th (K) Company. |
| 66th (C) Company. | 51st (G) Company. | 45th (L) Company. |
| 67th (D) Company. | 55th (H) Company. | 47th (M) Company. |
| 8th Machine Gun Company. | ||
| Supply Company. | ||
| Headquarters Company. | ||
SIXTH REGIMENT.
| First Battalion. | Second Battalion. | Third Battalion. |
| 74th (A) Company. | 78th (E) Company. | 82nd (I) Company. |
| 75th (B) Company. | 79th (F) Company. | 83rd (K) Company. |
| 76th (C) Company. | 80th (G) Company. | 84th (L) Company. |
| 95th (D) Company. | 96th (H) Company. | 97th (M) Company. |
| 73d Machine Gun Company. | ||
| Supply Company. | ||
| Headquarters Company. | ||
SIXTH MACHINE GUN BATTALION.
| 15th (A) Company. | 77th (C) Company. |
| 23d (B) Company. | 81st (D) Company. |
From June 27, 1917, to the middle of September, 1917, the Fifth Regiment was a unit of the First Division of Regulars. Although the Fifth Regiment was the only organization of Marines in France at the time, the Fourth Brigade of Marines was formed on October 23, 1917, when Col. Charles A. Doyen cabled acceptance of his appointment as Brigadier General. From October 26, 1917, to August 8, 1919, the Fourth Brigade was a part of the Second Division of Regulars, except from October 20-23, 1918, when the Brigade was provisionally at the disposal of the Ninth French Army Corps, in the vicinity of Leffincourt. On August 8, 1919, the brigade was transferred back to the naval service.
On May 29, 1917, in accordance with directions issued by the President, the Secretary of the Navy directed the Major General Commandant “to organize a force of Marines to be known as the Fifth Regiment of Marines for service with the Army as a part of the first expedition to proceed to France in the near future.” The Fifth Regiment was accordingly organized at the navy yard, Philadelphia, Pa., on June 7, 1917, with Col. Charles A. Doyen in command, and Maj. Harry R. Lay, as adjutant.
Gen. Pershing and his staff, accompanied by two Marine officers, preceded the first expedition to France, sailing late in May, 1917, from the United States.
The final report of the American commander in chief includes the following: