The unit was made up of volunteers from Maryland who, despite their home state remaining in the Union during the war, chose instead to fight for the Confederacy.

On April 19, Southern sympathizers in Baltimore attacked Union troops passing through by rail, causing what were arguably the first casualties of the Civil War.

Major General George H. Steuart, commander of the Maryland State Militia, and most of his senior officers were strongly sympathetic to the Confederacy.

[4] Captain Bradley T. Johnson, commander of Company A., refused the offer of the Virginians to join a Virginia Regiment, insisting that Maryland should be represented independently in the Confederate army.

In June 1861 General Johnston evacuated Harper's Ferry, and the 1st Maryland was ordered to assist in destroying its arsenal of weaponry.

The battle got off to a bad start when Elzey was forced to assume temporary command of the brigade, as General Smith was shot from his horse and injured by enemy fire.

However, Elzey was able to bring his men into line facing the flank of the Federal army, the brigade commanded by General Oliver O. Howard.

Steuart soon began to acquire a reputation as a strict disciplinarian, eventually gaining the admiration of his men,[5] though initially unpopular as a result.

"[8] According to Major W W Goldsborough, who served under Steuart at Gettysburg: "...it was not only his love for a clean camp, but a desire to promote the health and comfort of his men that made him unyielding in the enforcement of sanitary rules.

[9] George Wilson Booth, a young officer in Steuart's command at Harper's Ferry in 1861, recalled in his memoirs: "The Regiment, under his master hand, soon gave evidence of the soldierly qualities which made it the pride of the army and placed the fame of Maryland in the very foreground of the Southern States".

By this time Steuart had been promoted brigadier general, assigned with the task of forming the Maryland Line, and Colonel Bradley Tyler Johnson had succeeded to command of the regiment.

[3] By late summer the Southern capital of Richmond, Virginia was considered safe from Federal attack, and the Regiment's one-year term of duty having expired, it was soon disbanded.

[3] However, the soldiers of the disbanded regiment found themselves in a precarious position, being unable to return home to Union-occupied Maryland, having effectively committed themselves to the Confederacy for the duration of the war.

[3] The new regiment would suffer such severe casualties during the course of the war that, by the time of General Robert E. Lee's surrender at Appomattox Court House on April 9, 1865, only around forty men remained.