On April 6, 1917, the strength of the Marine Corps Reserve, all classes, was 36; the enlisted strength of the Naval Militia, Marine Corps Branch, of the various States, was 928.
On April 1, 1917, the Naval Militia, Marine Corps Branch, attained its highest strength, 1,046. There was no recruiting for the Naval Militia, Marine Corps Branch, after April 1, 1917, and in consequence, the enlisted personnel of that branch showed a steady decrease subsequent to that date, owing to discharges and rejections.
On July 1, 1918, the Naval Militia, Marine Corps Branch, then the National Naval Volunteers, Marine Corps Branch, consolidated with the Marine Corps Reserve in pursuance with the provisions of an act of Congress, approved July 1, 1918, and in consequence thereof became members of class 2, Marine Corps Reserve.
On November 16, 1918, the Marine Corps Reserve attained its highest strength, 6,773.
The following table shows strength of Marine Corps Reserve on active duty on November 11, 1918:
| Majors | 7 |
| Captains | 33 |
| First lieutenants | 63 |
| Second lieutenants | 360 |
| Total commissioned officers | 463 |
| Marine gunners | 27 |
| Quartermaster clerks | 2 |
| Pay clerks | 4 |
| Total warrant officers | 33 |
| Enlisted men | 6,483 |
| Female reservists | 277 |
| Total enlisted personnel | 6,760 |
Strength of the Marine Corps Reserve.
| Total men, all active. | Total men, inactive. | Women, active. | Women, inactive. | Total. | |
| 1917. | |||||
| Apr. 1 | 35 | .. | .. | .. | 35 |
| May 1 | 424 | .. | .. | .. | 424 |
| June 1 | 885 | .. | .. | .. | 885 |
| July 1 | 1,096 | .. | .. | .. | 1,096 |
| Aug. 1 | 1,167 | .. | .. | .. | 1,167 |
| Sept. 1 | 1,186 | .. | .. | .. | 1,186 |
| Oct. 1 | 1,210 | .. | .. | .. | 1,210 |
| Nov. 1 | 1,202 | .. | .. | .. | 1,202 |
| Dec. 1 | 1,341 | .. | .. | .. | 1,341 |
| 1918. | |||||
| Jan. 1 | 1,531 | .. | .. | .. | 1,531 |
| Feb. 1 | 2,514 | .. | .. | .. | 2,514 |
| Mar. 1 | 4,106 | .. | .. | .. | 4,106 |
| Apr. 1 | 4,745 | .. | .. | .. | 4,745 |
| May 1 | 4,780 | .. | .. | .. | 4,780 |
| June 1 | 4,950 | .. | .. | .. | 4,950 |
| July 1 | 5,211 | .. | .. | .. | 5,211 |
| Aug. 1 | 6,378 | .. | .. | .. | 6,378 |
| Sept. 1 | 6,453 | .. | 31 | .. | 6,484 |
| Oct. 1 | 6,402 | .. | 145 | .. | 6,547 |
| Nov. 1 | 6,467 | .. | 240 | .. | 6,707 |
| Dec. 1 | 6,440 | 42 | 269 | .. | 6,751 |
| 1919. | |||||
| Jan. 1 | 5,820 | 588 | 260 | .. | 6,668 |
| Feb. 1 | 5,022 | 1,301 | 255 | .. | 6,578 |
| Mar. 1 | 4,392 | 1,910 | 246 | .. | 6,548 |
| Apr. 1 | 3,555 | 2,684 | 234 | .. | 6,473 |
| May 1 | 3,064 | 3,041 | 229 | .. | 6,334 |
| June 1 | 2,871 | 3,179 | 238 | .. | 6,288 |
| July 1 | 2,410 | 3,502 | 226 | .. | 6,138 |
| Aug. 1 | 2,186 | 3,694 | .. | 201 | 6,081 |