From Hennessy:

Abraham Lincoln likely passed down the Sunken Road (coming toward the camera) in a four-horse carriage on May 23, 1862. This is a postwar image.
Abraham Lincoln was in the Sunken Road. I know it sounds like a bad plotline from the Twilight Zone, but it’s true.
Every once in a while you see something new in a picture even though you’ve looked at a hundred times before. The same is true with research. We have long known a good deal about Abraham Lincoln’s visit to Fredericksburg on May 23, 1862, during McDowell’s peaceful occupation of the town. After taking a boat to Aquia Landing, Lincoln took the trains to Potomac Creek Bridge, famously opted to walk across that seemingly flimsy structure (much to Secretary Stanton’s fright), and then on to Chatham. After reviewing some of the troops on the Stafford side, Lincoln crossed the Rappahannock on the canal boat bridge at the town docks and eventually proceeded to the Farmer’s Bank building on Princess Anne Street, where he met for a time with General Marsena Patrick, then governing the still-relatively placid population of Fredericksburg.
But recently reading through my notes and Ed Raus’s excellent Banners South, the history of the 23d New York Infantry (which includes by far the best published account of the Union occupation of Fredericksburg in the spring and summer of 1862), it became obvious that most references to Lincoln’s visit make mention of a detour Lincoln took beyond downtown Fredericksburg. General Marsena Patrick recorded in his diary that he “took [the President] through town to my camp.” The local Unionist newspaper, the Christian Banner, likewise noted that after visiting General Patrick in his quarters at the Farmer’s Bank building, Lincoln “moved off, as we were informed, to visit some camp of soldiers out of the town.” Fred Burrritt of the 23d New York, whose camp was atop Marye’s Heights on the site of what is today the National Cemetery (as carefully calculated by Ed Raus), recorded in a letter home that Lincoln visited the camps west of town. And J. Harrison Mills of the 21st New York, whose camp was on the heights between the Orange Plank Road (William Street) and Hanover Street, also wrote briefly of a presidential visit on May 23, as did a member of the 35th New York, nearby.
Given all that, it’s surprising the President’s visit to the troops on the Fredericksburg side of the river received such scant notice. One reason, certainly, is that his trip to Fredericksburg was quickly overshadowed by dramatic events in the Shenandoah Valley, as that very day Jackson was dispensing with Banks at Front Royal. But another reason the President’s journey received such scant attention from the troops is perhaps explained by Patrick. He said the President saw men “under arms only at the Guard,” but that other soldiers lounging in the camps turned out to have a look. In other words, Lincoln passed by, but there was no ceremony, no review.
It all seems a small matter, except for one curious thing: all this means that Abraham Lincoln very likely passed along Marye’s Heights or down the Sunken Road in May of 1862, six months before Union soldiers would attempt to claim the same ground in his name at the Battle of Fredericksburg.