[1] These·companies, Poland Guards,[note 1] Bellefontaine Rifles, Ohio Union Savers, and seven other volunteer companies, were ordered to Camp Chase, near Columbus, and were re-enlisted for three years and assigned to the regiment.
[8] This division of force elicited no response from the rebel military who had suffered crushing defeats in the in western Virginia and opted not to devote many resources to what they deemed an area of relatively limited value.
[8] In this area, the 23rd Ohio operated against numerous secessionist guerrillas there, performing hard duty, marching and countermarching over the rugged mountainous terrain drenched by almost continuous rain.
[3] Hope for real action rose in mid-August when Scammon was ordered south to join Rosecrans force assembling to counter a rebel offensive in the Kanawha Valley.
[15]Late Monday morning, September 9, the march resumed and that night halted 8 miles (13 km) from Summersville, on Muddlety Creek, on the site of a former Confederate outpost.
He then sent Benham's 1st Brigade down the road leading from Cross Lanes to the ferry in line of battle, cautioning him not to bring on an engagement as while Floyd's general location was known, the disposition of his troops was not.
[29] There was, however, no doubt some disappointment among the senior captains already with the regiment when Ohio Governor William Dennison dispatched Maj. James M. Comly to western Virginia to take Hayes' place.
[35] On Sunday, May 18, after destroying tents, camp, and garrison equipage, the regiment left Princeton and returned to Flat Top Mountain,[31] after having endured excessive hardships, defeat, and food shortages.
[19] The regiment remained at Flat Top Mountain until Sunday, July 13, when it was ordered northeast to Green Meadows, 7 miles (11 km) from Pack's Ferry, on New River.
A month later, Friday, August 15, Cox was ordered to march through the mountains by way of Staunton, and join Maj. Gen. Pope who commanded the newly created Army of Virginia, at Charlottesville.
[note 5] Having several detachments out pursuing guerrillas and scattered bands of Confederate troops operating in his rear near the Kentucky line, he would not be able to move for a few days.
[39] Other regiments had joined Pope to the south, but the 23rd Ohio remained with Cox just across the Potomac frrom the capital and was ordered into the fort on Upton's Hill to cover the front of Washington toward Centreville.
[3] Despite significant Confederates manpower losses over the spring and summer campaigns, Lee decided to invade Maryland and Pennsylvania, and cut off the B&O from Washington threatening the capital and Baltimore, to "annoy and harass the enemy.
"[44] McClellan, a strong organizer and a skilled trainer of troops, took command of the AoP, bolstered by units absorbed from Pope's army, included six infantry corps, about 102,000 men.
[note 6] On Friday, September 5, the 23rd Ohio and its division were ordered to march to Leesboro (present-day Wheaton, MD ) to join the Hooker's I and Burnside's IX Corps.
[46] Hayes later wrote in his diary that, in contrast to the rugged mountains of their former location, they marched through a "well-cultivated, beautiful region," with the heat and dust moderatedf by occasional rain.
The 23rd Ohio and its division were leading the advance and made contact with the Confederate rear-guard of cavalry under Hampton at the Monocacy River 3 miles (4.8 km) east of Frederick and drove them back into the town.
[19] The 23rd Ohio and other members of the Kanawha found that Frederick was a stronghold of unionists, and as Hampton's cavalry (Hill's rearguard) departed, "while the carbine smoke and the smell of powder still lingered,"[54] the local citizens warmly received them giving the column fruits and refreshments.
"[24] Hayes and his men did not get to tarry in Frederick, as McClellan continued to push his people forward, and the 23rd Ohio encamped Friday night just beyond the western edge of the town.
[60] As part of Hill's task of defending two northern gaps, as some of Lee's wagon train still had not gotten through,[note 10] he was also told to watch roads toward Harpers Ferry (then under siege by Jackson) to intercept any relief effort from McClellan.
These summits, scattered and somewhat irregular hills upon the high rounded surface of the mountaintop, were wooded, but along the open south-easterly slopes, quite near the top, there were small farms with meadows and cultivated fields.
The Federals would have to climb up the mainly open mountainside in view of the enemy, crossing across stonewalls and fields before entering the woods at the crest to drive the rebels off allowing the AoP to surge through and strike Lee before he could concentrate his army.
Telling him of his suspicions of the enemy, Cox also told him that he had Crook coming forward too, and if it became necessary to fight with the whole division, he would assume the responsibility as his senior officer for bringing on an engagement.
Hill instructed Garland to sweep through the woods, reach the Old Sharpsburg Road, and hold it all costs, as the safety of Lee's large train depended upon its being held.
Here, Cox overtook him, his brigade being formed in line, under cover of the timber, facing open pasture fields, having a stone-wall along the upper side, with the forest again beyond this.
[73] They were soon joined by the 23rd North Carolina on their left, which had advanced about forty yards from the ridge road in front of the Wise farm to counter White's, who had by then come up.
Garland's brigade managed one volley before the three regiments were on them and over the fence and walls,[76] dislodging the enemy and driving them into the woods beyond leaving a large number of their men killed by bayonet.
Armstrong, in Major McKinley, notes that while the future president held one of the more desirable, safer assignments in the regiment, he would find himself in dangerous situations, such as delivering rations in West Virginia to detachments or in foraging parties.
However, McClellan's limited activity on Monday, September 15, doomed the U.S. garrison at Harpers Ferry,[88] and gave Lee time to unite the rest of his army at Sharpsburg before the upcoming battle on Tuesday.
[47] On Monday, Lee deployed his troops behind Antietam Creek along a low ridge in an effective defensive, yet not impregnable, position with excellent cover for infantrymen, with rail and stone fences, outcroppings of limestone, little hollows and swales.