Massachusetts - Union
Cavalry
| 1st Regiment Cavalry | 2nd Regiment Cavalry | 2nd Battalion Cavalry |
| 3rd Regiment Cavalry | 4th Regiment Cavalry | 5th Regiment Cavalry (African Descent) |
| Devins' Battalion Mounted Infantry | Independent Battalion Cavalry |
Artillery
| 1st Regiment Heavy Artillery | 1st Battalion Heavy Artillery | 2nd Regiment Heavy Artillery |
| 3rd Regiment Heavy Artillery | 4th Regiment Heavy Artillery | 1st Company, Unassigned Heavy Artillery |
| 2nd Company, Unassigned Heavy Artillery | 3rd Company, Unassigned Heavy Artillery | 4th Company, Unassigned Heavy Artillery |
| 5th Company, Unassigned Heavy Artillery | 6th Company, Unassigned Heavy Artillery | 7th Company, Unassigned Heavy Artillery |
| 8th Company, Unassigned Heavy Artillery | 9th Company, Unassigned Heavy Artillery | 10th Company, Unassigned Heavy Artillery |
| 11th Company, Unassigned Heavy Artillery | 12th Company, Unassigned Heavy Artillery | 13th Company, Unassigned Heavy Artillery |
| 14th Company, Unassigned Heavy Artillery | 15th Company, Unassigned Heavy Artillery | 16th Company, Unassigned Heavy Artillery |
| 17th Company, Unassigned Heavy Artillery | 18th Company, Unassigned Heavy Artillery | 19th Company, Unassigned Heavy Artillery |
| 20th Company, Unassigned Heavy Artillery | 21st Company, Unassigned Heavy Artillery | 22nd Company, Unassigned Heavy Artillery |
| 23rd Company, Unassigned Heavy Artillery | 24th Company, Unassigned Heavy Artillery | 25th Company, Unassigned Heavy Artillery |
| 26th Company, Unassigned Heavy Artillery | 27th Company, Unassigned Heavy Artillery | 28th Company, Unassigned Heavy Artillery |
| 29th Company, Unassigned Heavy Artillery | 30th Company, Unassigned Heavy Artillery | Cook's Battery Boston Light Artillery |
| 1st Battery Light Artillery | 2nd Battery Light Artillery | 3rd Battery Light Artillery |
| 4th Battery Light Artillery | 5th Battery Light Artillery | 6th Battery Light Artillery |
| 7th Battery Light Artillery | 8th Battery Light Artillery | 9th Battery Light Artillery |
| 10th Battery Light Artillery | 11th Battery Light Artillery | 11th Battery Light Artillery (reorganized) |
| 12th Battery Light Artillery | 13th Battery Light Artillery | 14th Battery Light Artillery |
| 15th Battery Light Artillery | 16th Battery Light Artillery |
Infantry
| 1st Company Sharpshooters | 2nd Company Sharpshooters | 1st Battalion Infantry |
| 1st Regiment Infantry | 2nd Regiment Infantry | 3rd Regiment Infantry (3 months militia) |
| 3rd Regiment Infantry (9 months militia) | 3rd Battalion Rifles | 4th Regiment Infantry (3 months militia) |
| 4th Regiment Infantry (9 months militia) | 4th Battalion Infantry (militia) | 5th Regiment Infantry (3 months militia) |
| 5th Regiment Infantry (9 months militia) | 5th Regiment Infantry (100 days militia) | 6th Regiment Infantry (3 months militia) |
| 6th Regiment Infantry (9 months militia) | 6th Regiment Infantry (100 days militia) | 7th Regiment Infantry |
| 8th Regiment Infantry (3 months militia) | 8th Regiment Infantry (9 months militia) | 8th Regiment Infantry (100 days militia) |
| 9th Regiment Infantry | 10th Regiment Infantry | 11th Regiment Infantry |
| 12th Regiment Infantry | 13th Regiment Infantry | 14th Regiment Infantry |
| 15th Regiment Infantry | 16th Regiment Infantry | 17th Regiment Infantry |
| 18th Regiment Infantry | 19th Regiment Infantry | 20th Regiment Infantry |
| 21st Regiment Infantry | 22nd Regiment Infantry | 23rd Regiment Infantry |
| 24th Regiment Infantry | 25th Regiment Infantry | 26th Regiment Infantry |
| 27th Regiment Infantry | 28th Regiment Infantry | 29th Regiment Infantry |
| 30th Regiment Infantry | 31st Regiment Infantry | 32nd Regiment Infantry |
| 33rd Regiment Infantry | 34th Regiment Infantry | 35th Regiment Infantry |
| 36th Regiment Infantry | 37th Regiment Infantry | 38th Regiment Infantry |
| 39th Regiment Infantry | 40th Regiment Infantry | 41st Regiment Infantry |
| 42nd Regiment Infantry | 42nd Regiment Infantry (100 days militia) | 43rd Regiment Infantry |
| 44th Regiment Infantry | 45th Regiment Infantry (Cadet Regiment) | 46th Regiment Infantry |
| 47th Regiment Infantry | 48th Regiment Infantry | 49th Regiment Infantry |
| 50th Regiment Infantry | 51st Regiment Infantry | 52nd Regiment Infantry |
| 53rd Regiment Infantry | 54th Regiment Infantry (African Descent) | 55th Regiment Infantry (African Descent) |
| 56th Regiment Infantry | 57th Regiment Infantry | 58th Regiment Infantry |
| 59th Regiment Infantry (4th Veteran) | 60th Regiment Infantry | 61st Regiment Infantry |
| 62nd Regiment Infantry | 1st Unattached Company Infantry | 2nd Unattached Company Infantry |
| 3rd Unattached Company Infantry | 4th Unattached Company Infantry | 5th Unattached Company Infantry |
| 6th Unattached Company Infantry | 7th Unattached Company Infantry | 8th Unattached Company Infantry |
| 9th Unattached Company Infantry | 10th Unattached Company Infantry | 11th Unattached Company Infantry |
| 12th Unattached Company Infantry | 13th Unattached Company Infantry | 14th Unattached Company Infantry |
| 15th Unattached Company Infantry | 16th Unattached Company Infantry | 17th Unattached Company Infantry |
| 18th Unattached Company Infantry | 19th Unattached Company Infantry | 20th Unattached Company Infantry |
| 21st Unattached Company Infantry | 22nd Unattached Company Infantry | 23rd Unattached Company Infantry |
| 24th Unattached Company Infantry | 25th Unattached Company Infantry | 26th Unattached Company Infantry |
| Boston Cadets Salem Cadets |