Location and date of this incident can be confirmed, but not the claims. The wartime list of battles and skirmishes composed by officers of the 13th Alabama mentions nothing between Chancellorsville and Gettysburg, but does include small actions like Gaines Crossroads VA, July 25, 1863.

Federal reports submitted during the first week of June 1863 place Archer's Brigade opposite Port Conway.

On June 7th the O.R. mentions VI Corps headquarters at Mansfield, AKA Barnard House. According to the 1860 census, three older Barnard women lived on this plantation, about a mile south of Fredericksburg VA. The Fredericksburg Country Club is here today. General Sedgewick placed his line of pickets along Bowling Green Road (modern-day Routes 2 and 17), just west of the Rappahannock River.
http://www.mycivilwar.com/battles/630605.htm

Evidently this early June action was photographed from the east bank of the river --
http://www.civilwarphotography.org/hidden-in-plain-sight