We now recrossed Beverly Ford and went into camp until the 12th. Then we learned that the Confederate army was on the move toward the North, and that our army was marching to Manassas Junction and Centerville. We therefore marched in the same direction, and on the 16th rejoined our Corps near Centerville. Reaching Leesburg on the 18th, we went into camp. We had no definite information as to the location of the Confederate army, but rather suspected that it was moving into the Shenandoah Valley. This suspicion was confirmed when we learned that they had occupied Winchester and Martinsburg. We heard of them next as crossing the Potomac at Williamsport and marching into Pennsylvania.

During our stay at Leesburg, several men from a New York regiment were shot for desertion. They were the first executions for that crime in our army, and for a time, they produced a great sensation. On the 26th we crossed the Potomac at Edward's Ferry, and proceeded up the river to the mouth of the Monocacy; thence we moved across to Frederick City, where we went into camp early on the afternoon of the 28th.

During the night I learned that our Division was under marching orders to strike for Williamsport in the morning, and destroy the bridge on which the enemy had crossed the Potomac. We were to destroy, also, all boats and ferries that might be used by the Confederates in a retreat. Then we were to rejoin the army if we could; if not, to move west to Cumberland, and rejoin as opportunity offered. With morning, however, came a change of commanders, and with it also, a change of orders. General Hooker had been superseded by General Meade, and now we were ordered northward to follow the army that had gone ahead.

At noon on July 1, while we were preparing our dinner at Two Taverns, some eight miles south of Gettysburg, the distant rumbling of artillery to the north announced to us the opening of a great battle. The cannonading became more and more furious as the minutes passed, until in the distance it sounded like one continual roll of thunder. At length came the order to march, and in five minutes we were on the road to the front as fast as our strength could take us. As we trudged along, we met hundreds of Confederate prisoners being sent to the rear, as well as a good many of our own wounded, on their way to the field hospitals. Of stragglers, there were exceptionally few.

On the run we reached Cemetery Ridge, where we learned that the First and Eleventh corps had been compelled to fall back through the town of Gettysburg. They had taken a new position on a ridge east of the city. A portion of our Brigade now filed off to the right, across Rock Creek, thence north about half a mile; and then, having deployed about half of our Regiment as skirmishers, advanced toward the west until we were sharply engaged with the enemy's skirmishers. Only a little over two hours had passed from the time when we received the order to march eight miles distant, before we were in position on the extreme right of the line of battle, checking the advance of the enemy in that direction. There we remained until sunset, when we were relieved by the cavalry, and recrossed Rock Creek to the west side.

As the remainder of our Corps had come up, they took position on the right of the First Corps. We now rejoined them there, our own right resting on Rock Creek. Immediately we began to throw up breastworks, and by evening had built for ourselves quite respectable entrenchments. It rained during most of the night; but in spite of that and the enemy, we secured a good rest for the next day's work.

Early the next morning we were stirring, in anticipation of an attack; but until noon there was nothing but skirmishing in our vicinity. Then the storm broke loose on the extreme left of the line, near Little Round Top, where Sickles's Corps was situated. The place was entirely hidden from our sight, and from the sounds we could form no opinion as to how things were going; but we were constantly receiving reports that Sickles was either holding his own or driving the enemy before him. In the light of subsequent events, these reports seem to have been purposely colored, in order to keep up our spirits. Occasional demonstrations along our front kept us in constant expectation of being attacked, but nothing of the sort occurred.

About six o'clock we were hurried out of our entrenchments at a double-quick toward Little Round Top, where it was understood that Sickles's Third Corps had been driven back with severe loss. But before we arrived, the enemy had been repulsed, and the firing ceased. We were now started back to our entrenchments. We found, however, upon our arrival, that the enemy had in our absence taken possession of them. It was exasperating to see them benefitting by our labors, but we were somewhat consoled by the capture of a picket of twenty Confederates, who in the darkness had wandered into our line as we approached. We were now obliged to form a new line, connecting with our forces on the left as before, but swinging back at an angle on the right to Rock Creek. We thus presented to the enemy a semi-circular front, which they could not penetrate without being subjected to a cross fire from both sides.

During the night we remained unmolested. At daylight the firing commenced. The ground occupied by the enemy's skirmishers was a rocky bit of woodland which furnished abundant cover for sharpshooters. For a while they annoyed us, but by nine o'clock we had dislodged them, and driven them back to the cover of their breastworks. On our left the enemy were making desperate efforts to dislodge from their entrenchments Greene's Brigade and the troops of the First Corps. Six times they came up to the assault, and six times were repulsed, leaving the ground over which they advanced literally covered with their dead. At about eleven o'clock a portion of our Division followed up these successes by charging the Confederates in our front and sweeping them entirely out of our entrenchments. They retired only a short distance, however, showing that they had not abandoned the contest.

For nearly two hours, complete quiet now succeeded the roar and din of the battle. Not a cannon was fired. Only an occasional musket shot disturbed the silence that prevailed from one end of the field to the other. We all felt, however, that this was but a lull before the final burst of the storm. The losses in our Regiment had thus far been light, and our spirits ran high. We felt entire confidence that no force that the Southerners could bring against us could by direct assault break our line at any point.

About one o'clock, the first shot was fired in the tremendous artillery duel that preceded the last desperate attempt to penetrate our center at Cemetery Ridge. In five minutes three hundred guns were pouring into one another, their deadly showers of shot and shell, and making fearful havoc of every thing that was not sheltered. From our position in the woods we could see nothing of what was going on in other parts of the line; but the air above was filled with screaming shells, as they flew back and forth on their deadly errand. In some instances, shells from the Confederate batteries in front of the Second Corps would pass entirely over our lines, and land near the enemy in our front; a great many of them fell in the open space in our rear.

At one time during the progress of the cannonade, a battery was placed in position on a hill across Rock Creek directly in front of our Regiment, and began to drop shells unpleasantly close to us. But our friends of Battery M, of the First New York Artillery, who had been with us since the Brigade was organized, seemed to get their range at once, and promptly silenced them. On a trip over the field, the next day, I found the position where they had been stationed marked by a dozen dead horses and two exploded caissons.

During the cannonading, I took occasion to go back into the woods a short distance in order to get a view of what was going on. Everything in sight gave evidence of the severity of the fire. All those who were not actively engaged had sought the shelter of rocks and trees or the inequalities of the ground. Here and there mounted officers and orderlies were riding across the field, although at first sight it seemed as though a bird could scarcely fly over it unharmed.

In the course of an hour the terrific artillery fire slackened. Then for a few minutes it nearly ceased. In the interval of silence, Pickett's Division of Confederates was marching to the charge. From my position I could not see them coming on, but I knew that they were charging by the old familiar Southern yell. Soon that was drowned in the roar of musketry and artillery. For a time all was turmoil and confusion. At length the hearty cheers of our comrades rang out, and we knew that the Confederate tide of invasion had been safely rolled back.While this assault was being made on the center, constant demonstrations were being made on our front, and we momentarily expected an attack. None came, however, although during all the rest of the day the enemy presented an unshaken line. At night they silently withdrew, and on the morning of the 4th our reconnoitering parties could find nothing of them east of Seminary Ridge, save their dead and severely wounded, whom they had left on the field.

I spent some time that day going over the ground occupied by the enemy in front of the Twelfth Corps, and that over which Pickett had made his now famous charge. From what I saw, I felt certain that the enemy's losses were double our own. Where they had assaulted Geary's Division on the evening of the 2nd and on the morning of the 3rd, the ground was so strewn with their dead that it would have been possible to walk for rods on dead bodies.

On the morning of the 5th the enemy was on the road back to Virginia. We started the same day following hard after them, on parallel roads to the east. When they reached Williamsport, however, they turned on us with a bold front. It had been raining almost constantly for several weeks and the Potomac was a raging torrent, which could not be forded. We were in hopes that it might thus continue until our forces could be concentrated to overwhelm them. On the morning of the 13th, however, when we were ready to move forward to the attack, they were gone. The river had fallen during the night, and they had made good their retreat.

For a time our Regiment led in the pursuit to the ford at Falling Waters. Then we were filed out to the side of the road to make way for General Kilpatrick's Cavalry Brigade. They had scarcely passed out of sight through a patch of woods, when the roar of artillery and the sharp crack of musketry announced that the enemy had been found. We moved forward as rapidly as possible, but were not in time to take any part in the conflict. It appeared that when the cavalry had emerged from the woods they had found a brigade of Confederate infantry posted as a rear guard, on a ridge overlooking the ford at Falling Waters. They had immediately charged the enemy's breastworks and had captured over a thousand prisoners. They had won, besides, as trophies of their skirmish, two pieces of artillery and four or five colors inscribed with all the battles of the Army of Northern Virginia. No further pursuit was made. All of Lee's army, save only this rear guard, had escaped safely to the south side of the Potomac.

At about this time I sent to my home in Wisconsin the following letter concerning Lee's invasion:

I have wished a good many times that the rebs could have had a month more among the people of Pennsylvania. What little sympathy I had for them is gone now. I cannot appreciate that disposition which will swindle a friend to compensate for what an enemy has stolen from you. In some cases the farmers would sell our men provisions at reasonable rates and even give them something, but the majority would ask from $.60 to $1.00 a loaf for bread, and $.25 a quart for milk, and all such things in proportion.

Our Corps now moved down the river to Harpers Ferry, and crossing into Virginia, marched leisurely along the eastern side of the Blue Ridge. We found the abandoned fields through which we passed overgrown with blackberry bushes, and literally black with the ripened fruit. Every night the men would go out from camp, and within easy range find as many berries as they could eat. And they were the best medicine we ever used. I knew of cases of diarrhea that had become almost chronic, soon cured by this diet.