The Vanderburg’s House was three miles north of Munson Hill and would be the scene of a friendly fire incident. The Confederates continued to send out night patrols trying to identify where Union picket lines were located. On one such patrol near Chain Bridge Captain Lingenfelter of Colonel Baker’s 71st PA (1st CA) was killed. This and similar events prompted General William F. Smith to send two divisions to the Munson Hill area to put an end to the Rebel activity. One of the regiments failed to receive their orders and when General Smith arrived to move them out he found them asleep. The 71st PA (1st CA) was in the lead under Lieutenant Colonel Isaac Wistar and moved out from Camp Advance at 9:30 P.M on the 28th. His column was made up of a battalion of nine companies, followed by Mott’s battery of 4 guns, followed by a second battalion of seven companies under Major Parrish. In addition to the 71st PA (1st CA) other troops in the column were from the 69th PA (2nd CA), and the 2nd and 3rd VT. Wistar arrived opposite the Vanderburg’s house at  11:00 P.M. His column was stopped here for about two hours while a number of felled trees blocking the road were cleared. Wistar describes in the Official Record the confusing events that followed

“My instructions from General Smith were to proceed with advance guard or flankers until I should pass Colonel Burnham, who with his regiment was near the next cross-roads, and after passing him, he being the most advanced of our forces, to throw out three companies deployed as skirmishers across the road, and follow them with the column at a distance of, say, 150 yards, connecting the head of the column with the center of the skirmishers by a file of men at intervals of 10 paces. This had just been accomplished, when General Smith himself, with staff, overtook me, and the whole was immediately put in motion. After proceeding a short distance I was surprised to find a picket guard of a New York regiment, having supposed we had passed all of out own outposts. At the first turn to the right, which occurred within a quarter of a mile after the deployment of my skirmishers, they began to come in collision with picket guards, who said they belonged to the Fourth Michigan. The road at this point was lined with thick woods on both sides. At the turn of the road was stationed in the road a picket of, say, 20 men; 30 yards beyond was another of, say, 6 men, and the head of the column had not progressed more than 50 yards past the latter, the skirmishers being ahead and on both flanks entangled among the pickets in the woods on the left, when a regular volley was fired into the second and third companies of my line from immediately behind the fence which lined the woods on my left. The head of the column having now passed the woods on our right, the latter was replaced by open fields, exposing us to the light of the rising moon, while the woods on our left, whence an invisible enemy continued to pour his fire, was in deep shade. Considerable confusion took place in the column thus suddenly attacked. Nothing was advisable in the woods but the flashes of their guns; but, convinced the firing was the mistake of friends, I rode between my men, who had instantly faced towards the woods whence the firing proceeded, vainly calling upon all parties to cease firing. At this moment my horse was shot and rendered nearly unmanageable, and notwithstanding my exertions, firing commenced among my own men, who could bear it no longer, and continued perhaps for two minutes, when the party in the woods retired. I now ordered my killed and wounded to be carried to the rear and dressed my line, and was endeavoring to reassure all parties, when the parties in the woods, having returned suddenly, threw in another volley from not less then forty paces, as I should judge, which my men instantly returned without orders, the distance being the width of the road-say 6 yards. This time the firing extended nearly as far back in the road as the rear of my first battalion, producing a panic among the artillery horses, who turned and dashed off to the rear, breaking loose from the guns, and producing great confusion in my second battalion by rushing over them at full speed. A number were shot, and the remainder turned off the road, which soon restored order. After sending my killed and wounded to the rear, I put my command in the woods which concealed the firing party, whoever they may have been, thoroughly scoured and took possession of it, and with the valuable aid of Adjutant Newlin drew up in line of battle along its front to hold the road, at the same time stationing my second battalion, under command of Major Parrish, who was of very great assistance during the whole night and whose perfect coolness during such general confusion was very gratifying, in the woods at the right, so as to cross fires with the first battalion on the road in front, and then, after rallying my skirmishers and distributing them as pickets all around our front, reported these dispositions to General Smith, who was pleased to approve them. On the following afternoon, at 4 p. m., I left the position by General Smith’s order, and marched back to this camp, where I arrived, without further incident, at dark.”

It is hard to determine who was firing on who but it appears that after encountering the 4th Michigan the 71st PA (1st CA) were fired into by the 5th PA “Cameron Dragoons”. In the confusion and darkness the 2nd CA (69th PA) fired into the 1st CA (71st PA). The Dragoons also fired into the 2nd VT. Wistar’s regiment suffered 4-9 killed and 14-25 wounded, two of them were seriously injured by the fleeing horses and the gun carriages they were pulling.

Sources

The Glories of War, Small Battles and Early Heroes of 1861 by Charles P. Poland

War of the Rebellion: Serial 005 Page 217 Chapter XIV Ohio State University

A Virginia Village Goes to War, Falls Church in the Civil War by Bradley E. Gernand.

Chronology of the Civil War in Fairfax County Part I by Edward T. Wenzel.