[2] Recruited chiefly from the counties of Norfolk, Bristol, and Plymouth, it then moved to at Camp Brigham[3][note 1] in Dedham for basic training.

Five companies reached the rendezvous early in July, 1861, by direction of the governor when the defeat at Bull Run shook Washington, DC.

Orders to report with the command at Washington were then received, and the journey began on the 28 August, with a full complement of officers, and eight hundred and ninety-one men.

The regimental camp was located near Fort Corcoran, on ground recently occupied by the Sixty-ninth New York, and the Eighteenth began to see actual service in fatigue duty and on picket.

This position was occupied during the winter, the regiment giving much attention to drill and discipline, so that at a review held at Bailey's Cross Roads it was especially complimented for excellence by the commander in chief, and as a mark of appreciation received new uniform and camp equipage imported from France and modeled on that of the French chasseurs a pied.

Up the south side of the latter the division marched, setting out on the 13th, going first to Cumberland, thence to White House, moving on the 19th toward Richmond as far as Tunstall's Station, and on the 26th to Gaines Mills.

There it remained until 26 June, when with the Seventeenth New York of Butterfield's Brigade it was detached from the division to accompany a force of cavalry and artillery under General Stoneman for the protection of the army supplies at White House.

With the rest of the army, the Eighteenth encamped at Harrison's Landing until 15 August, the only movement of note during that time so far as they were concerned being a reconnaissance to the Chickahominy the last of July, returning to camp the same day.

An attempt was then made to advance across a field and through a piece of woods, by which it was hoped to flank a Confederate battery; but the failure of troops to the right and left to advance rendered the attempt futile; the brigade was soon obliged to half and answer the fire which was poured in from front and both flanks, and after half an hour of this unequal contest the decimated regiments fell back to a less exposed position, Syke's Division (Second) of the same corps covering their withdrawal.

He was soon promoted to the vacant lieutenant colonelcy, Captain Thomas being made major; the commissions dated from 25 August, but it was some time later that the recipients were mustered to the new rank.

Then began the march to the Antietam, where the Fifth Corps arrived on the 16th, but beyond supporting batteries on the east side of the creek the Eighteenth took no active part in the engagement.

After the fighting was over the regiment was detailed for picket near the Burnside bridge, at the left, where it passed the 18th and the succeeding night, advancing the next day to the Potomac.

The movement southward began on 30 October, when the column marched toward Harper's Ferry, crossed the Potomac there the following day and advanced by easy stages to Warrenton, where it went into camp on the 9th.

Camp was broken on the 17th, the regiment moving by way of Elktown to Hartwood Church, encamping there from the 19th to the 23d and then advancing to a position on the railroad near the village of Falmouth.

After falling back it was reformed and again took its place in the front of the Union line where it remained during the rest of the afternoon and in that vicinity until the evening of the next day, when it retired to the town and early the next morning as part of the rear guard covered the withdrawal of the troops from that side of the river.