The Patapsco Guards performed guard duty and provost duty at Ellicott's Mills, as well as York, Chambersburg and Harrisburg, Pennsylvania. During the Gettysburg Campaign the guards skirmished with part of Lee's 2nd Corps at Wrightsville, Pennsylvania.
During General McCausland and General Johnson's raid on Chambersburg in July of 1864, the Patapsco Guard skirmished with Confederates near Chambersburg on July 30th.
On expiration of the company's term of service those men wishing to leave the service were mustered out, those veterans who remained and new recruits remained in service until August 17, 1865.
The company lost 4 men to disease during the course of the war.
History provided by Gary Baker of the Association of Carroll's Sacred Trust.