Following the Battle of Cross Keys, the Thirteenth Battery was deployed on a march to the Rapidan River near Culpepper Court House, and then back again. In late August, they found themselves engaged in numerous skirmishes along the Rappahannock River near Sulphur Springs and Waterloo Bridge as forces converged towards the Second Battle of Bull Run. The following two letters from William Wheeler to his mother describe the Battery's activities through his eyes. The first letter was written only a few days following the Second Battle of Bull Run, which occurred on Friday and Saturday, Aug 29-30, 1862.

HEAD-QUARTERS 13TH N.Y. BATTERY,
NEAR CHAIN BRIDGE, VA., September 5, 1862.

DEAREST MOTHER, — I take the first opportunity offering itself to give you intelligence of my entire safety and welfare, if it be only a few lines. I was in the hottest of the fight all day Friday, and all the afternoon of Saturday, and exposed myself considerably to keep our boys up to the scratch, but got nothing except a slight scrape on the top of the head from a piece of a shell, and a bruise on the cheek from a canister ball; both of these little wounds are almost quite well, and almost without medical assistance, and I sincerely recognize the protecting hand of God in my preservation. The Battery did right gallantly, though I say it that should not, and were highly praised by General Sigel. As soon as I get the chance I will write again. This must suffice for the present. Very much love to all.

CAMP NEAR FORT ETHAN ALLEN, VA.,
September 10, 1862.

DEAREST MOTHER, — Your welcome letter has just come to hand, giving me assurance that you had got my hastily-penned note, and were relieved from all immediate and harassing anxiety on my account. I did the best I could to communicate with you, but on account of our being so constantly on the move, officers always in the saddle, and horses in the harness, it was impossible to call the next five minutes our own; so I could only send you a pair of words. I think you can hardly fail to be interested in my experiences for the last three weeks. My last letter to N.H. [New Haven - ed.] was written to A. from the banks of the Rapidan, and in that I remember I spoke of the speedy advance of our forces in the direction of Gordonsville; how ignorant I was of the state of affairs was proved by the fact that the very next evening we had orders to be ready to march to the rear in an hour, and before the sun went down our long, slow-moving trains were drawing off in the direction of Culpepper Court House. Our Corps, which had the post of honor in the rear, drew out into the road, and lay there all that night, and a good part of the next day, waiting until the enormous trains and the Corps in front of us should have reached the positions assigned to them. We passed through the foul region of Slaughter Mountain, with great offense to eye and nose; the men had all been buried, but the pile of slaughtered horses still showed where batteries had stood in the hottest fire. We passed through Culpepper that afternoon, and, by dint of steady marching, came to the Rappahannock in the night. Here we took up a position to cover the passage of the river, and stood to our guns until about noon the next day, when we, too, passed over, and the bridge was burned behind us. Thence on from Jeffersonville to White Sulphur Springs, - the Saratoga of the South; but the place of the summer loungers in the streets was filled with soldiers, and the sick men lay in the great hotels which had, two years before, been so full of "dances and delight." Here we hoped for a day's rest, so much needed by both men and horses, but we were allowed only one good sleep, and then off again, after breakfast, to the Rappahannock, along whose banks a fierce, long-range artillery duel was to be kept up for about a week. The first day our four rifled guns came into action, my six-pounders being kept in reserve as too short range. One of our gunners made a splendid shot that day, at over a mile, and dismounted a secesh gun, but this feat was ascribed in the papers to Captain Schirmer's Battery, as have half a dozen things that our Battery has done. The only loss that our artillery sustained that day was Captain Buell, commanding the reserve artillery, and just the man that we could worst afford to lose. A shell, passed through his horse, wounding him in both legs, and then the horse fell on him, and caused internal injuries, of which he died that same evening. He was really a charming fellow, quiet, gentle, yet firm and active; his whole Battery loved him to devotion, and I enjoyed his society greatly, ever since we came under his command at Sperryville. For the next two days we had plenty of marching, but little fighting. The next day we were separated from the reserve artillery, and sent to General Milroy's, and ever since we have been connected with this king of the bush-whackers. We have not had occasion to complain that we have been neglected, in getting our full ration of fighting. In fact, before we had been with him two hours he had the rifled guns in full operation on a hill, while I crept forward with my two pieces towards a hill well in the advance. We were well covered by our own pieces until we reached the brow of the hill, and came into battery in an apple orchard; we drove the enemy's cavalry out of the woods, but could not do much to the enemy's battery, which was too long range for us, and their balls and shells tipped the trees about us in a lively manner. The chief of artillery saw that we did not reach them, and ordered us down the hill again; pretty soon Sigel came along and saw my section standing idle, and inquired the reason; upon hearing that Captain Schirmer had sent me back, he said, "Take your section up on the hill again and fire away;" so up I went to a part of the hill more directly in front of the enemy's batteries. Instead of stopping on the summit, I had my guns run down the easy slope towards the enemy, by hand, and thus advanced until I was several hundred yards in front of our line, and had brought the hostile batteries completely within my range; then we went to work, and, by keeping sharp look-out, succeeded in shutting up every gun which the Rebs planted in front of us. Once they ran a gun well up before a bank and masked it, so that it fired three times before I could exactly find it; when I did, I laid my two guns right for the muzzle, and it assumed a dignified silence. By afternoon our Brigade moved further on, and we had no more work of importance till the evening before Friday's battle. Then we shelled the woods where the enemy lay, just at nightfall, and the shells with their burning fuses made a beautiful firework. That night each cannoneer slept at his post by the gun, and we all snoozed soundly, for we knew that we should have plenty to do the next day, and having seen Jackson's handiwork at Manassas, were right anxious to go on and catch the old Valley Fox, whom we had been so long hunting. Alas, it turned out too much like the story of the man who caught the Tartar. Up early, placed our Battery in a commanding position, and engaged a hostile battery for an hour or two, until we drove them away, and then advanced to their position. (N.B. This credited in the newspapers to Schirmer's Battery.) Beyond was a high ridge, on which the enemy had many batteries planted, and a large part of his force concentrated to attack this. Milroy now advanced with his Brigade, and our Battery alone, being only supported by long range fire from batteries on the ridge we had left. He entered a piece of open ground, behind the woods which sheltered him from the batteries on the hill, and throwing skirmishers and a regiment into the woods on the right, tried to carry the railroad embankment in his front. The Battery was not placed in position, but just stood close behind the infantry in column, utterly useless, and itself in danger, After a sharp fight in the woods, our men had to retire, when suddenly a couple of rebel brigades came swarming over the railroad embankment, and our Brigade had to beat a hasty retreat. We did not move until the enemy were pretty near, and then we went back through the opening, the bullets flying in great abundance. Just as my second piece had passed the opening, a shot brought down one of the pole horses, and stopped us short; my first thought was, "The piece is lost;" my next, "It shall be sold dear," and I sprang down, and with the assistance of one man, unlimbered it. I seized the rammer, and we had one shot fired before the other officers knew that we were in danger, The other cannoneers came up, but I held on to the rammer, and did Number One in pretty lively style. The other pieces came into battery on a hill behind us, and opened fire; then the batteries above us began to operate at short range, and between shells, canister, and musketry fire, we had it hot enough. But we soon drove the infantry back to the embankment, and gave our infantry a chance to halt and reform. A reserve horse had been brought up with harness, and was hitched in under the hottest fire; when all was ready, I had the piece limbered up, and followed the rest of the Battery to the opening in the fence. Just at the opening, the reserve horse was shot two or three times, and I had to cut him out of the harness and carry the branch myself for some distance. While acting as Number One, I was struck on the cheek by a canister shot and thought I was hurt, but it swelled two days and then passed off. A splinter of shell struck me on the head, cutting three little holes, and burying itself next the bone. This grew very sore, and the doctor, after taking out a piece of my felt hat, which was driven in also, tried to extract the metal, but could not do it. However, I have poulticed it, and it has healed up entirely. (This exploit of ours, which saved the Brigade, is attributed in the newspapers to Hampton's Pittsburg Battery. I don't care a cent for newspaper praise, but it comes hard for the men to have others steal their well-earned laurels.) In the afternoon we were sent to an important position, from which the rebels had already driven two or three of our batteries. They had got the range exactly, and threw every shell right among us. However, we held the position until our ammunition was exhausted. The fire was really infernal, and we lost several men killed or badly wounded, and many horses. I was astonished to find that the idea of danger was so little present with me, even in the hottest of the fire: but I suppose that it was because I kept myself occupied and worked hard at my duty. A shell struck the piece I was working, and ploughed a great furrow down it; but I hardly noticed it at the time. In fact, I think that the extreme front is the safest as well as the most honorable place. I have seen many a man knocked over by these bounding shots, when he thought he was all safe in the rear. We are hoping soon to get into Washington to refit, as we have lost many horses, and want some of our guns mended. In our General (Sigel) we have the most entire confidence, and his corps will follow him anywhere. ....I need rest greatly, and to recruit my health. I would rather stand by my post, and trust to time and rest to heal me, than to go into hospital. I am afraid this egotistical letter may have wearied you.