After serving additional garrison duty in Hampton, Virginia, the regiment returned to Boston and was mustered out on July 22, 1861.

[citation needed] The 4th Massachusetts was summoned for active service on April 15, 1861, in response to President Lincoln's call for 75,000 troops to put down the insurrection in the southern states.

Despite the various companies being dispersed over a large area of southeastern Massachusetts, the regiment was present for duty in Boston on the evening of April 16 and were barracked that night in Faneuil Hall.

[7] The regiment arrived via the steamship State of Maine at Fortress Monroe, a Union foothold on the Virginia coast, in the morning of April 20, 1861.

[2] On May 27, 1861, the 4th Massachusetts was ordered by Major General Benjamin Butler, then in command of Union troops on the Virginia coast, to occupy newly constructed fortifications at Newport News.

At Camp Butler for the next two weeks, the 4th Massachusetts worked on expanding and improving fortifications, conducted guard duty and occasional light scouting expeditions.

[8] On June 19, 1861, five companies of the 4th Massachusetts under the command of Major Horace O. Wittemore (consisting of about 300 men) were ordered to join several other regiments in an expedition to attack the Confederate position at Big Bethel, about 12 miles from Newport News.

Even after this debacle, which caused great disorder among many of his troops, the Union officer in command of the expedition, Brigadier General Ebenezer W. Pierce, decided to proceed with the attack.