The last campaign of the Sixth was very brief, and equally monotonous. There was a hiatus between the expiration of the time of some of the veteran regiments and the coming in of new organizations for three years, when the govern ment called for regiments for one hundred days. There were several of the State militia organizations anxious to respond, five of which came forward promptly, within a week or two of each other. The first one ready, as usual, was the Sixth. Its services were offered to the government early in July, and accepted; and it took camp July 13, in Readville, Lieut.-Col. Beal commanding the companies as fast as they arrived. The companies were mustered in the following order: Co. K, on the 14^th; Cos. A, I, and G, on the 15^th; Cos. C, F, D, and H, on the 16^th; Co. B, on the 17^th, and Co. E, on the 19^th. The colonel, lieutenant-colonel, adjutant, surgeon, and first assistant-surgeon were mustered on the 17^th, and the time of service dated from the 20^th, on which day it left camp, with thirty-six officers and nine hundred and ninety-four enlisted men. It immediately proceeded to Washington, via Groton, Conn., New York, Philadelphia, and Baltimore, arriving in the capital on the 22^d. The reception in Baltimore, on this its third march through the monumental city towards the South, was very gratifying; and the officers were assured that their command was distinguished for its excellence of deportment, among the six hundred thousand who at that time had passed "through Baltimore."

Source: "Historical Sketch of the Old Sixth Regiment of Massachusetts Volunteers during its Three Campaigns" by John H. Hanson, Chaplain of the 6^th Regiment, published in 1866. This book is online at Archive.org.