OVERVIEW:
"Western Bay State Regiment," organized at Pittsfield, November 20, 1861, to February 20, 1862. Duty at Camp Chase, Lowell, till February, 1862. Moved to Boston February 19, thence sailed on steamer "Mississippi" for Ship Island, Miss. Detained at Hilton Head, S. C., repairing vessel, March 1-13. Arrived at Ship Island March 23, and duty there till April 18. Attached to 2nd Brigade, Dept. of the Gulf, to October, 1862. Sherman's Division, Dept. of the Gulf, to January, 1863. 3rd Brigade, 3rd Division, 19th Army Corps, Dept. of the Gulf, to July, 1862. 2nd Brigade, 1st Division, 19th Army Corps, Dept. of the Gulf, to December, 1863. 4th Brigade, Cavalry Division, Dept. of the Gulf, to June, 1864. Defences of New Orleans to September, 1864. 1st Brigade, Cavalry Division, Dept. of the Gulf, to October, 1864. Defences of New Orleans to March, 1865. 1st Brigade, Lucas' Cavalry Division, Steele's Command, Military Division West Mississippi, to April, 1865. District of Mobile, Ala., to September, 1865.

SERVICE:
Operations against Forts St Phillip and Jackson, Mississippi River, April 18-28, 1862. Moved to New Orleans April 29-30. Occupation of New Orleans May 1. (The first Union Regiment to enter city.) Provost duty at New Orleans till August Garrison duty at Forts St. Phillip and Jackson till January, 1863. (3 Cos. at Fort Pike till September, 1863. Rejoined Regiment September 9.) Skirmish at Bayou Bontecou November 21, 1862, and Deserted Station December 10. Moved to Carrollton January, 1863, and duty there till March 6. Moved to Baton Rouge March 6-7. Expedition to Port Hudson March 7-27. Moved to Algiers April 1, thence to Berwick City April 9. Operations in Western Louisiana April 9-May 14. Teche campaign April 11-20. Fort Bisland April 12-13. March from Opelousas to Alexandria and Simsport May 5-18. Moved to Bayou Sara, thence to Port Hudson May 22-25. Siege of Port Hudson May 25-July 9. Skirmish at Thompson's Creek May 25 (Detachment). Assaults on Port Hudson May 27 and June 14. Expedition to Clinton June 3-8. Surrender of Port Hudson July 9. Moved to Baton Rouge July 11, thence to Donaldsonville July 15-August 1. Moved to Baton Rouge September 1 and duty there till December 9. Moved to New Orleans December 9 and there converted into a Cavalry Regiment known as 6th Massachusetts Cavalry. Bonfonca November 26. Duty at Carrollton till February 29, 1864. March to Berwick Bay and Brashear City February 29-March 9. Red River Campaign March 10-May 22. Advance to Alexandria March 11-26. Bayou Rapides March 20. Monett's Ferry and Cloutiersville March 29-30. Natchitoches March 31. Crump's Hill, Piney Woods, April 2. Wilson's Farm April 7. Bayou de Paul, Carroll's Mill and Sabine Cross Roads April 8. Pleasant Hill April 9. Monett's Bluff, Monett's Ferry, April 23. Hudnot's Plantation May 1. Near Alexandria May 2-9. Retreat to Morganza May 13-20. Near Alexandria May 14. Mansura May 16. Near Moreauville May 17. Yellow Bayou May 18. At Morganza till July 3. Expedition to the Atchafalaya May 30-June 6. Expedition to Tunica Bend June 19-21. Moved to New Orleans July 3. Veterans absent on furlough July 21 to September 19. Non-Veterans guard prisoners at New Orleans till September --. Duty in Defences of New Orleans till March, 1865. Non-Veterans mustered out November 19, 1864. Ordered to Donaldsonville November 27, and operating against guerrillas till February, 1865. Operations near Hermitage Plantation December 14, 1864, to January 5, 1865. Expedition from Plaquemine to the Park January 26 to February 4 (Detachment). Skirmish at the Park February 4 (Detachment). Consolidated to a Battalion of five Companies. Ordered to Carrollton February 9, 1865; thence moved to Barrancas, Fla., March 6-9. March to Fort Blakely, Mobile Bay, March 20-April 1. Siege of Fort Blakely April 1-9. Occupation of Mobile April 12 and duty there till September. Mustered out September 9, 1865. Moved to Boston September 11-24, and discharged September 30, 1865.
Regiment lost during service 52 Enlisted men killed and mortally wounded and 3 Officers and 150 Enlisted men by disease. Total 205.