On April 15, 1861, the day following the surrender of Fort Sumter, President Abraham Lincoln issued a call for 75,000 volunteers for three months service. The next day, New Hampshire Governor Ichabod Goodwin issued a call for one regiment of volunteers. The Civil War lasted four years rather than three months and before it ended in April of 1865, New Hampshire had supplied the Union with eighteen regiments, including two cavalry units, four artillery units and three companies of sharpshooters.

Over 38,943 New Hampshire residents served during the War - approximately 12 percent of the state's population (1860 Census). 32,486 served in New Hampshire units, 3,160 enlisted in the U. S. Navy, and 396 joined African-American regiments. By war's end, 1,934 New Hampshire soldiers and sailors had died from war wounds, 2,407 from disease, and 499 died from undetermined causes.

Organized at Manchester from 200 men left over from the forming of the 3rd Regiment. The regiment was mostly natives of New Hampshire with the exception of Company G, which was made up of stout-hearted Irishmen. Company A enlisted at Dover, Company B at Nashua, Company D at Laconia, Company F at Great Falls, Company H at Salem, Companies C,E,G,I, and K were mostly Manchester men. Part of Company E was enlisted at Pittsfield. The 4th Regiment was mustered into service September 18, 1861, and moved to Washington, D.C., September 27-30; thence to Annapolis, Md., October 9. Attached to Casey's Provisional Brigade, Army of the Potomac, October, 1861. Wright's 3rd Brigade, T. Sherman's South Carolina Expeditionary Corps to March, 1862. District of Florida, Dept. of the South, to September, 1862. Brannan's Brigade, District of Beaufort, S.C., 10th Corps, Dept. of the South, to April, 1863. United States Forces, Folly Island, S.C., 10th Corps to June, 1863. 1st Brigade, United States Forces, Folly Island, S.C., to July, 1863. 1st Brigade, 1st Division, Morris Island, S.C., 10th Corps, July, 1863. 1st Brigade, Morris Island, S.C., to January, 1864. District of Beaufort, S.C., to February, 1864. Foster's Brigade, Dodge's Division, District of Florida, February, 1864. District of Beaufort, S.C., to April, 1864. 1st Brigade, 3rd Division, 10th Corps, Army of the James, Dept. of Virginia and North Carolina, to May, 1864. 3rd Brigade, 3rd Division, 18th Corps, Army of the Potomac, to June, 1864. 3rd Brigade, 2nd Division, 10th Corps, to December, 1864. 3rd Brigade, 2nd Division, 24th Corps, to March, 1865. 3rd Brigade, 2nd Division, 10th Corps, Dept. of North Carolina, to August, 1865.

SERVICE.-- Expedition to Port Royal, S.C., October 21-November 7, 1861. Capture of Forts Walker and Beauregard, Port Royal Harbor, November 7. Duty at Hilton Head, S.C., until January 21, 1862. Expedition to Florida January 21- March 2. Occupation of Fernandina, Fla., March 5. Occupation of Jacksonville, Fla., March 12 to April 8 (Cos. "E" and "F," Provost duty at Fernandina until April.) Regiment moved from Jacksonville to St. Augustine, Fla., April 9, and garrison duty there until September 6. (Cos. "B," "H" and "K" moved to James Island, S.C., June 8. Action on James Island June 10. Moved to Beaufort, S.C., June 12, and duty there until April, 1863.) Regiment moved from St., Augustine, Fla., to Beaufort, S.C., September 6, 1862, and duty there until April, 1863. Expedition to Pocotaligo, S.C., October 21-23, 1862. Action at Caston and Frampton's Plantations, Pocotaligo, October 22. Expedition against Charleston April 4-11, 1863. Expedition to North Edisto River April 17-28. Moved to Folly Island, S.C., April 29, and siege operations against Morris Island until July.

Expedition to James Island July 9-16. Secessionville July 16. Siege operations against Forts Wagner and Gregg, Morris Island, S.C., and against Fort Sumter and Charleston until January, 1864. Capture of Forts Wagner and Gregg September 7, 1863. Moved to Beaufort, S.C., January 17. Expedition to Whitmarsh Island February 20-22, 1864. Moved to Jacksonville, Fla., February 23, and return to Beaufort, S.C., February 26. Veterans on furlough March-April. Non-Veterans at Beaufort until April 12, then ordered to Gloucester Point, Va. Butler's operations on south side of James River and against Petersburg and Richmond May 4-27. Capture of Bermuda Hundred and City Point May 5. Chester Station May 6-7. Swift Creek (or Arrowfield Church) May 9-10.

Operations against Fort Darling May 12-16. Drewry's Bluff May 14-16. Bermuda Hundred May 16-27. Moved to White House Landing, thence to Cold Harbor May 27-June 1. Battles of Cold Harbor June 1-12. Before Petersburg June 15-19. Siege of Petersburg June 16 to December 7. Duty in trenches before Petersburg June 23 to July 30. Mine Explosion July 30. Demonstration north of James River August 13-20. Strawberry Plains August 14-18. Bermuda Hundred August 24-25. Duty in trenches before Petersburg until September 25. (Non-Veterans mustered out September 18, 1864.) New Market Heights, Chaffin's Farm, September 28-30. Duty on north side of the James, operating against Richmond, until December 7. Fair Oaks October 27-28. Expeditionto Fort Fisher, N. C., December 7-27. 2nd Expedition to Fort Fisher January.

The 4th is regarded as one of New Hampshire's best regiments and performed a valuable service in the South during the war. The regiment was mustered out on August 23, 1865, having suffered 1,759 casualties and 185 deaths in the 16 major engagements it was involved in.