He was transferred to the United States Army Ordnance Department to serve at Benicia Arsenal near San Francisco, California in October 1860, where he was promoted to the permanent rank of second lieutenant from November 22, 1860.

[8] Following the siege of Fort Sumter in April 1861, Lieutenant Randol was ordered east from Benicia Arsenal to join the fighting in the Eastern Theater.

At the time he joined, the battery included subordinate section chiefs Lieutenants Samuel S. Elder, Lorenzo Thomas Jr., and Theophilus Bhyrd von Michalowski[11][12] and was armed with four 12-pounder cannons and two 6-pounder howitzers.

[18] Traveling by sea and landing at Fortress Monroe, Battery E & G joined the Siege of Yorktown, then moved westward with the Army of the Potomac to the Chickahominy River.

After General Robert E. Lee's Army of Northern Virginia shook McClellan's confidence with a string of heavy blows opening the Seven Days Battles at Beaver Dam Creek/Mechanicsville and Gaines' Mill, the Union commander ordered his bloodied V Corps (then north of the Chickahominy) to return south of the river and follow the rest of the Army of the Potomac on a retreat toward the perceived safety of the banks of the James River near Harrison's Landing.

Horse Artillery Brigade alongside McCall's division late in the afternoon of June 29 as it marched from the White Oak Swamp toward its overnight objective: the defense of the critical junction of the New Market and Quaker Roads at Glendale, where the whole of the Army of the Potomac would be required to pass on its route across Malvern Hill and onward to the James River.

Meade discovered the error around midnight on June 30, when Averell and Benson's advanced pickets met Confederate skirmishers moving in the opposite direction.

[25][26] Randol's own cannoneers reported encountering Confederate sentries in the dark approximately 100 yards (91 m) west of their guns, then-deployed in an open field north of the New Market Road.

[1][27] At approximately 4:00 AM on June 30 the battery moved east with McCall's column while it retraced the path to Glendale, the vanguard of the division arriving after dawn and believing it had proceeded safely beyond Federal lines.

McCall's men waited for orders until approximately noon, unaware that they were, in fact, representing the extreme western flank of the Union Army while the Confederate main force under Major Generals James Longstreet and Ambrose Powell Hill were rapidly approaching to assault the crossroad.

[1][28] It was not until Meade and Seymour personally reconnoitered the trees to the west of the open field in which the division was bivouacked that they discovered there was practically nothing standing between the approaching rebels and McCall's line.

Soon afterward, the cannonry stopped and heavy fighting took place as Confederate units emerged from the woods opposite McCall in piecemeal fashion, offering probing attacks along the whole line.

The difficulty of the terrain and poor communication prevented the combined assault envisioned by Lee, which allowed the Federals to focus on repulsing isolated attacks as they occurred.

Though Randol's cannoneers managed a single discharge of double-shotted canister in their own defense, Confederate infantry swarmed the battery and overran his guns, driving the gunners from their posts at the point of bayonet and back to his line of ammunition caissons.

[27] As the morning of July 1, 1862 dawned and Lee's Confederates approached to renew hostilities at the Battle of Malvern Hill, Randol's remaining enlisted men were temporarily attached to Lieutenant Edmund Kirby's Battery I, 1st U.S.

[12][34] After the Army of the Potomac settled into its new camp at Harrison's Landing on the James River, Randol was breveted to the rank of captain for "gallant and meritorious services in action" at Glendale, effective June 30, 1862.

[33] He wrote to Meade (then recuperating from his Glendale wounds in Philadelphia), who provided a glowing letter of reference which absolved him from blame and instead placed the fault squarely upon his own Pennsylvania Reserves infantry regiments in support:You may rest assured that if I do make a report I shall do full justice to the coolness and good conduct exhibited by yourself and the Staff Officers and men under your command on that unfortunate day.

I am also aware, and shall so state, that the loss of your battery was due to the failure of the Infantry supports to maintain that firm and determined front which I should have expected from my men had not their morale been impaired by the fatigues incident to previous battles, constant marches, loss of rest and want of food, exhausting their physical energies to such a degree that they were not able to withstand the desperate and determined onslaught of overwhelming numbers causing them to give way sooner than under other circumstances I should have expected them to have done.

[40] During the Battle of Antietam on September 17, the battery was detached from Sykes' division to General Alfred Pleasonton's Cavalry Corps with units of the Horse Artillery Brigade.

The rebel artillery was driven back, but Randol's battery remained in reserve for the rest of the engagement; the majority of the fighting that day took place to the northwest and southwest of their position.

[42] In early November, the V Corps moved with the Army of the Potomac to join its newly appointed commander Major General Ambrose Burnside's campaign against Lee at Fredericksburg, Virginia, with Battery E & G engaged along the way at Snicker's Gap.

Artillery joined Burnside's infamous Mud March of January 1863, finally entering winter camp and remaining until April 28, 1863, when Battery E & G struck out for Chancellorsville, Virginia, arriving May 1, 1863.

Attached to Federal cavalry in pursuit of the Confederates moving northward toward Pennsylvania (eventually to Gettysburg, Pennsylvania), Randol's battery was constantly in battle, and learned to fight like horse artillerymen utilizing rifled guns on the front line of battle rather than placed toward the rear and supported by infantry as they had been previously: We were frequently on the skirmish line, and sometimes in advance of it, and drove the enemy's batteries and cavalry from all their positions as fast as selected, dismounting some of his guns, blowing up limbers and caissons, and killing many men and horses.

In May 1864, Battery H & I joined Major General Ulysses S. Grant's Overland Campaign, present during the battles of the Wilderness and Spotsylvania Courthouse with the Artillery Reserve and later attached to the Second Division of the Cavalry Corps, Army of the Potomac in June.

"[51] Toward the end of the fight, the regiment was preparing to make a final desperate charge against a fortified Confederate artillery position–an action which Randol himself described as suicidal– when the enemy raised the white flag of surrender:About daybreak I was aroused by loud hurrahs, and was told that Ord’s corps was coming up rapidly, and forming in rear of our cavalry.

It was fortunate for us that we halted when we did, for had we charged we would have been swept into eternity, as directly in our front was a creek, on the other side of which was a rebel brigade, entrenched, with batteries in position, the guns double shotted with canister.

Artillery regiment, including Battery L, was transferred to the Department of the Pacific on the West Coast of the United States and posted at the Presidio (Fort Winfield Scott) in San Francisco, California.

Artillery in 1875,[12] and wrote another essay about his experience at the head of the 2nd New York Cavalry Regiment under Custer during the Battle of Appomattox Station in April 1865, published while he was posted in San Francisco in 1886.

[45][59] This was possibly the result of his history of exposure to yellow fever while serving in the Southern United States during the Civil War and while posted in Texas and Florida post-war.

[8][52][62] On November 22, 1886, Randol left on sick leave from Fort Canby for the warmer climate of San Francisco; he died of his illness on May 7, 1887, in New Almaden, California.