McClellan's Epidemic: Disease and Discord at Harrison's Landing, July–August 1862

As he sat down to write a letter on July 20, 1862, Brig. Gen. David B. Birney had recently survived the hardest week of his Civil War experience to date. After lingering in the Chickahominy swamps and fighting to a standstill in the Seven Days' battles, the Army of the Potomac under Maj. Gen. George B. McClellan retired to a new position nestled in the humid marshes and meadows along the James River southeast of Richmond. There, the battered and traumatized army faced a new threat—rampant diseases that exacted an unprecedented toll on the troops. Birney summarized the army's plight when he wrote to a friend, "Malaria has decimated our troops. We have lost more by fatigue [and] exposure … than we would have in twenty battles."¹

The last six weeks of George B. McClellan's 1862 Peninsula campaign deprived his army of as many effective soldiers as Ulysses S. Grant's six-week bloodletting from the Wilderness to Petersburg in 1864. The difference between the Overland campaign and the 1862 campaign lay in the nature of those casualties: Grant's persistence against the Army of Northern Virginia cost nearly 55,000 combat losses, while most of McClellan's number came from diseases contracted during occupation of the Chickahominy River and, especially, Harrison's Landing on the James River. Records indicate the Army of the Potomac exhibited 42,911 cases of various illnesses in July 1862, while the month of August, half of which witnessed the army still languishing on the James River, totaled 20,836 cases. Furthermore, most of these losses came on top of an official total of 15,855 combat casualties from the Seven Days' battles proper.

To be sure, remarkably few of McClellan's soldiers actually died from the summer outbreaks, but the lack of a stark mortality statistic should not cloud the fact that diseases like diarrhea and malaria lingered with the affected soldiers for weeks and even months. Kathryn Shively Meier's groundbreaking study of the environment and soldier identity in 1862 Virginia has established that many soldiers recognized the threats of such disease outbreaks. Official army medical systems failed widely enough that soldiers adopted self-care methods for health maintenance, Meier insists. But even these efforts of individual soldiers could not keep up with the scale of the Harrison's Landing health crisis, where diseases incubated in the Chickahominy swamps hatched to render the summer of 1862 a landmark medical catastrophe in American military history.²

This article bridges the two topics of Civil War disease and army politics by arguing that the summer of 1862 shaped the partisan dynamic inside the Army of the Potomac for the rest of the war. It begins with evidence that the six weeks on the James River from July 2 to August 15, 1862, were an unprecedented medical disaster for the United States Army. Coming on the heels of the Seven Days' battles, this experience with disease drained the army. Harrison's Landing, therefore, energized the emergence of a partisan divide in the army because soldiers expressed such intense and public disgust with their situation, their leadership, and the progress of the conflict. On the Peninsula, these volunteers dealt with the physical and psychological aftermath of a massive and costly campaign for the first time. While the army languished, its naïve rage militaire of 1861 evaporated, and officers and men wondered aloud what their sacrifices had achieved. Who was to blame for the failure to take Richmond and end the war? Survivors of the Seven Days looked at the crowded hospital tents of an army entrenching just miles from the Confederate capital and came to believe they were the victims of mismanagement somewhere at the top.³

Historians have filled insightful volumes discussing how the Seven Days battles upset the war's balance and turned the Confederate war effort in a different direction under Robert E. Lee.⁴ Likewise, McClellan's biographers have dissected his famous "Harrison's Landing Letter" to President Lincoln, which offered policy advice on emancipation and...