Organized as "Eastern Bay State Regiment" at Camp Chase, Lowell, by Gen. B. F. Butler, December 31, 1861. Moved to Boston January 2, 1862. Mustered into United States service as 30th Massachusetts Infantry January 4, 1862. Sailed from Boston on steamer "Constitution" for Fortress Monroe, Va., January 13, arriving January 16; thence sailed for Ship Island, Miss., February 6, arriving there February 12, and duty there till April 15. (Co. "K" joined March 9.) Attached to 3rd Brigade, Dept. of the Gulf, to October, 1862. Defences of New Orleans to January, 1863. 3rd Brigade, 1st Division, 19th Army Corps, Dept. of the Gulf, to August, 1863. 1st Brigade, 1st Division, 19th Army Corps, Dept. of the Gulf, to July, 1864, and Army of the Shenandoah, Middle Military Division, to March, 1865. 1st Brigade, 1st Provisional Division, Army of the Shenandoah, to April, 1865. Dept. of Washington to June, 1865. Dept. of the South to December, 1865.

SERVICE:
Operations against Forts St. Phillip and Jackson, Mississippi River, April 15-28, 1862. Occupation of Fort St. Phillip April 28. Moved to New Orleans April 29-30. Occupation of New Orleans May 1. Expedition to New Orleans & Jackson Railroad May 9-10. Moved to Baton Rouge May 30-31. Expedition from Baton Rouge June 7-9. Williams' Expedition to Vicksburg, Miss., and operations in that vicinity June 18-July 23. Ellis Cliff June 22. Hamilton Plantation, near Grand Gulf, June 24. Moved to Baton Rouge July 23-26, and duty there till August 21. Battle of Baton Rouge August 5. Moved to Carrollton August 21-22, and duty there till November 4. Garrison duty at New Orleans till January 13, 1863. Moved to Baton Rouge January 13-14. Expedition to Port Hudson March 7-27. Operations against Port Hudson May 12-24. Monett's Plantation and on Bayou Sara Road May 18-19. Plain's Store May 24. Siege of Port Hudson May 24-July 9. Assaults on Port Hudson May 27 and June 14. Surrender of Port Hudson July 9. Cox's Plantation, Donaldsonville, July 12-13. Camp at Baton Rouge August 1-September 2. Sabine Pass Expedition September 4-11. Moved from Algiers to Brashear City September 16, thence to Berwick and to Camp Bisland September 26. Western Louisiana ("Teche") Campaign October 3-November 30. At New Iberia till January 7, 1864, and at Franklin till February 18. Veterans on leave February 18-May 3. Moved to New Orleans May 3-16, and to Morganza June 13. Moved to New Orleans, thence to Fortress Monroe. Va., and Washington, D. C., July 2-13. Snicker's Gap Expedition July 14-23. Sheridan's Shenandoah Valley Campaign August to December. Battle of Opequan, Winchester, September 19. Fisher's Hill September 22. Mt. Jackson September 23-24. Battle of Cedar Creek October 19. Duty at Winchester, Kernstown and Stephenson's Depot till April 1, 1865. Moved to Washington, D. C., April 21-22, and duty there till June 1. Grand Review May 23-24. Moved to Savannah, Ga., June 2-6, thence to Georgetown, S. C., June 13, and to Florence June 27. To Sumpter July 9. Duty in 3rd Sub-District Eastern South Carolina till December. Mustered out December 1, 1865.
Regiment lost during service 4 Officers and 57 Enlisted men killed and mortally wounded and 2 Officers and 341 Enlisted men by disease. Total 404.