37th Massachusetts Tree


Not much happened on this part of the battlefield, as discussed on the page dedicated to the Trees of Shame nearby. We may note that this tree stands in the area where all of the battlefield’s main monuments to the Sixth Corps are located, including a tablet, the headquarters cannon, and the equestrian statue of Maj. Gen. John Sedgwick. The 37th Massachusetts Volunteer Infantry (2nd Brigade, 3rd Division) stood, according to its right flank marker (which stands behind the 5th Corps headquarters cannon nearby), 100 yards to the east of its monument on today’s Sedgwick Avenue. Consequently, the witness tree standing behind the monument to the 37th Massachusetts, to complement the Trees of Shame just to the north, will be dedicated to the much-maligned Union officer, Brig. Gen. Thomas A. Rowley, in an attempt to rehabilitate his historically slandered reputation.

The definitive study of the history of Rowley’s career, performance at Gettysburg, and subsequent court martial was performed by John F. Krumwiede, which he published under the title, Disgrace at Gettysburg (Jefferson, NC: McFarland & Company, Inc., 2006).


This tree was first photographically identified by Greg Gober, using the images appearing in Figures P-1 and P-2 below.

Brig. Gen. Thomas A. Rowley (USA) Witness Tree

Figure P-1: The Thomas A. Rowley Witness Tree can be easily discerned behind the small rock which sits 25 feet behind the 37th Massachusetts monument on Sedgwick Avenue.

Tree Species: white oak
Circumference 2023: 98.5”
Diameter: 31.4”
Calculated Average Growth Rate: 6-7 years / inch diameter
Estimated age: 200-215 years
Estimated diameter in 1863: 6.5-8”
GPS: 39.797046N, 77.234118W

This hefty white oak appears in two William Tipton photographs of the monument to the 37th Massachusetts Volunteer Infantry on Sedgwick Avenue (see Figures P-1 and P-2). The two images were taken about two decades apart, and a careful analysis suggests the ratio of the tree’s diameter in 1896:2023 to be 0.41, and for 1915:2023 to be a little larger as expected, coming in at 0. 47. Our witness tree should be easily at least 200 years old, and probably had a diameter of 6.5-8 inches during the Battle of Gettysburg.

This witness tree is named for Brig. Gen. Thomas A. Rowley, commander of the 1st Corps’ 3rd Division on the first day of the Battle of Gettysburg. (1)

Before Gettsyburg

Thomas A. Rowley was born sometime in the late 1810s in Pittsburgh, PA. As a young man, he entered politics, serving as a ward alderman and clerk of courts. More importantly, he joined a local militia in 1839, beginning a 24-year military career. When war with Mexico commenced in 1846, Rowley’s militia unit was mustered into federal service and shipped south. Rowley was a Second Lieutenant. Rowley participated in the fighting at Vera Cruz, where he was struck several times by spent balls, but received no serious injury. He resigned during the unit’s march to Mexico City due to “severe disease” affecting one of his feet. (2)

Figure P-2: both the 1896 image shown here and the later one of Figure P-1 were taken by William H. Tipton.

While recuperating, Rowley raised another militia unit, the Rough and Ready Guards, which travelled in 1847 to Mexico, where he and his men spent the rest of the war fighting guerillas and in garrison duty. In 1855, Rowley joined a new militia unit, the Washington Infantry of Pittsburgh, and was promoted to captain 1858. (3)

When war with the south broke out, Rowley was elected colonel of a three-month regiment, the 13th Pennsylvania, of which the Washington Infantry comprised three companies. At the expiration of the unit’s time, Rowley raised a new Allegheny County regiment, the 102nd Pennsylvania Volunteer Infantry. The regiment first came under fire at during the Peninsular Campaign, where Rowley and his men performed well, Rowley being commended by his brigade commander, Brig. Gen. John J. Peck, for his performance at Williamsburg, Seven Pines (where he was struck on the back of the head by a musket ball), and Malvern Hill. (4)

Disaster at Gettysburg

In late 1862, Rowley was given command of his brigade, and was promoted to brigadier general in November. He commanded a brigade at Chancellorsville, and was given a division – the 3rd Division of the 1st Corps – for the first time at Gettysburg, where he performed ably in the fighting on Seminary and McPherson’s Ridge. (5)

But it was during the retreat when Rowley began to show signs of the mental strain that would end tragically for him. His trouble started when he picked a fight with Brig. Gen. Lysander Cutler during the retreat through town. Once on Cemetery Ridge, Rowley behaved erratically, complaining about the cowardly officers of the 7th Wisconsin, appearing unsteady on his horse, and even repeatedly claiming to be in charge of the 1st Corps, using his supposed command status to move troops not actually under his command. Lt. Clayton Rogers, an aide to 1st Corps division commander Brig. Gen. James S. Wadsworth, watching Rowley raving and acting “positively insane”, believed Rowley to be drunk, and, together with Lt. Col. Rufus Dawes, arrested the general, who apparently surrendered his sword without demur. (6)

Interestingly, Rowley remained on the field throughout the remainder of the battle, even receiving shrapnel wounds in the leg on July 3rd. However, the damage was done. Rowley was reassigned on October to command a recruiting depot in Maine, where he stagnated for over half a year, until he was ordered to return in April 1864 to the Army of the Potomac, which was in Virginia at the time. (7)

Court Martial

Brig. Gen. Thomas Rowley in colonel’s uniform. At 5’5″ and 200 pounds, Rowley may not have possessed a particularly martial bearing, but he was popular with his men, and had never shown any sign of incompetence before the Gettysburg campaign. Image from the Library of Congress.

Rowley was to be disappointed to learn that rather than be given a command, he was instead to face a court martial for his behavior on July 1 at Gettysburg, based on charges brought by Lysander Cutler. Rowley was charged with, amongst other accusations, drunkenness and using threatening language to give orders to troops not under his command. The court, made up of nine general officers, was clearly hostile to the accused. All but one of the judges were West Point graduates, who typically viewed volunteer generals with disfavor. The evidence of Rowley’s alleged drunkenness was given by officers who did not know the general personally, but only witnessed his actions on July 1. For his defense, Rowley provided testimony from numerous junior officers who had known him for a very long time, and had never seen him inebriated or act incompetently in any manner prior to Gettysburg. (8)

Despite the conflicting evidence, the Court Martial found Rowley guilty of most of the charges, and he was sentenced to be dismissed from the army. Following procedure, a record of the trial was sent to the President, who, as a lawyer, recognized the unjustness of the verdict, and reversed it, with the concurrence of the judge advocate general, Col. Joseph Holt. Unfortunately, Rowley was not to be trusted with campaigning troops again, and spent the remainder of the war in Pittsburgh, where he was placed in charge of the District of Monongahela. Brig. Gen. Thomas Rowley resigned from the army in December 1864, and, after practicing law and serving as a U.S. Marshall, died in 1892, and was buried in Allegheny Cemetery. (9)


Rowley’s biographer, John Krumwiede, concludes the court martial and verdict against Rowley to have been patently unfair, and observes that the general’s erratic behavior on Cemetery Hill could easily be explained by his likely suffering heat stroke at the time. The fact that he had fallen off his horse twice on July 1, which was used against him in his court martial, is also easily explained, since it was known, and explained to the court, that he was suffering from large and agonizing boils on the inside of his upper thighs, which meant that he could barely ride his horse properly. 

Now long forgotten, the affable, popular, and thoroughly competent Thomas Rowley deserves to have his reputation rehabilitated. Even if he was not a lion on the battlefield in the mold of an A.P. Hill or Winfield Scott Hancock, he does not deserve to be remembered only on mocking lists of the worst generals at Gettysburg.

(1) The definitive study of the history of Rowley’s career, performance at Gettysburg, and subsequent court martial was published by John F. Krumwiede under the title, Disgrace at Gettysburg (Jefferson, NC: McFarland & Company, Inc., 2006). It is from this book that most of these notes on the “life of Rowley” are adapted.
(2) Krumwiede, pp. 1-5.
(3) Ibid.
(4) Ibid, pp. 6-34.
(5) Ibid, pp. 59-87.
(6) Ibid, pp. 88-94.
(7) Ibid, pp. 97-107.
(8) Ibid, 108-136.
(9) Ibid, pp. 140-1.
Rowley is conspicuously absent from the narratives of Philip Laino and Bradley Gottfried: Laino’s only comment (p. 143) about him is, “Rowley…may be drunk;” Gottfreid  (p. 100) at least gives him credit for sending the 151st Pennsylvania onto McPherson’s Ridge to try to stem the flow of the swarming Confederates, but nothing else. 
Harry Pfanz, in Gettysburg: The First Day, mentions Rowley as encouraging his men in a couple of places before objectively describing his inexplicable behavior on Cemetery Ridge (p. 328). But on page 354, the author reviews the devastating consequences to Rowley’s career caused by his “drunken behavior on 1 July”, subtly avoiding a direct assertion that Rowley was in fact drunk! (Pfanz, Harry W. Gettysburg: The First Day. Chapel Hill, NC: The University of North Carolina Press, 2001)