Twelfth regiment Massachusetts Infantry.
| Field and Staff. | Line. | companies. | Unassigned Recruits. | Totals. | ||||||||||
| A | B | C | D | E | F | G | H | I | K | |||||
| Killed and died of wounds,— | ||||||||||||||
| Officers, | 4 | 13 | – | – | – | – | – | – | – | – | – | – | – | 17 |
| Enlisted men, | – | – | 19 | 17 | 15 | 14 | 21 | 17 | 20 | 11 | 13 | 13 | – | 160 |
| Totals, | – | – | – | – | – | – | – | – | – | – | – | – | – | 177 |
| Missing, | – | – | 3 | 2 | – | 2 | 2 | – | – | – | 2 | – | – | 11 |
| Died by accident or disease,— | ||||||||||||||
| Officers, | – | – | – | – | – | – | – | – | – | – | – | – | – | – |
| Enlisted men, | – | – | 9 | 6 | 10 | 4 | 2 | 5 | 3 | 6 | 5 | 5 | – | 55 |
| Died as prisoners,— | ||||||||||||||
| Officers, | – | – | – | – | – | – | – | – | – | – | – | – | – | – |
| Enlisted men, | – | – | 3 | 1 | – | 2 | – | 6 | 2 | 4 | 7 | 2 | – | 27 |
| Total losses,— | ||||||||||||||
| Officers, | 4 | 13 | – | – | – | – | – | – | – | – | – | – | – | 17 |
| Enlisted men, | – | – | 34 | 26 | 25 | 22 | 25 | 28 | 25 | 21 | 27 | 20 | – | 253 |
| Totals, | – | – | – | – | – | – | – | – | – | – | – | – | – | 270 |
| 1862. | ||||||||||||||
| Aug. 9, Cedar Mt., Va., | – | 2 | – | – | – | – | – | – | – | – | – | – | – | 2 |
| Aug. 28, Thoroughfare Gap, Va., | – | – | – | – | – | – | – | – | – | 1 | – | – | – | 1 |
| Aug. 30, 31, Manassas, or Bull Run, 2d, Va | 1 | 1 | 2 | 3 | 3 | 5 | 1 | 5 | 2 | – | 2 | 1 | – | 26 |
| Sept. 14, South Mt., Md., | – | – | – | – | – | – | 1 | – | – | – | – | – | – | 1 |
| Sept. 17, Antietam, Md., | 2 | 3 | 10 | 7 | 4 | 4 | 11 | 2 | 7 | – | 9 | 7 | – | 66 |
| Dec. 13, Fredericksburg, Va., | – | 1 | 4 | 3 | 2 | 1 | 1 | 2 | 3 | 3 | – | 4 | – | 24 |
| Dec. 18, Front of Fredericksburg, Va. | – | – | – | – | – | – | – | 1 | – | – | – | – | – | 1 |
| Place unknown, | – | – | – | 1 | – | – | 4 | – | 1 | – | 1 | – | – | 7 |
| 1863. | ||||||||||||||
| July 1-3, Gettysburg, Pa., | – | 2 | 1 | 1 | 2 | – | 1 | – | 1 | 2 | 1 | 1 | – | 12 |
| July 8, Funkstown, Md., | – | – | – | – | – | – | 1 | – | – | – | – | – | – | 1 |
| Place unknown, | – | – | 1 | – | – | – | – | – | – | – | – | – | – | 1 |
| 1864. | ||||||||||||||
| May 5-8, Wilderness, Va., | 1 | – | 3 | 3 | 2 | 5 | – | 3 | 3 | 3 | 1 | – | – | 24 |
| May 8-14, Spotsylvania, Laurel Hill, Va. | – | 3 | 2 | – | – | – | – | 4 | 2 | 1 | – | – | – | 12 |
| May 24, North Anna River, Va., | – | 1 | – | – | – | – | – | – | – | – | – | – | – | 1 |
| June 1-3, Bethesda Church, Va., | – | – | – | – | 1 | – | – | – | – | – | – | – | – | 1 |
| June 18-21, Petersburg, Va, | – | – | – | – | 1 | – | 1 | – | 1 | 1 | 1 | – | – | 5 |
| Place unknown, | – | – | – | – | – | 1 | 2 | – | – | – | – | – | – | 3 |
