On Independence Day in 1863, a Saturday, it was raining in Gettysburg, Pennsylvania, as burial details and medical officers took account of the recent battle. Some 50,000 men had fallen in three days, 8,000 of them killed outright and the rest in need of medical attention. Civilians working independently or under the auspices of the US Sanitary Commission, a relief organization established in 1861 to lend a hand to the Army Medical Department, poured into town as overtaxed surgeons worked around the clock and local citizens came up for air. By Sunday, with so many bodies left to bury and 3,000 horse carcasses littering the roads and fields, relief workers arriving from Washington, Philadelphia, and Baltimore could smell decay from miles away and recorded their revulsion at the stench.
The prospect of providing timely aid to so many was daunting. No one had anticipated this many casualties, and the medical corps was ill prepared. The germ theory was not yet widely understood, so few surgeons practiced antisepsis, which meant that patients with fair chances of recovery sometimes contracted blood poisoning or gangrene and died. Anesthesia, on the other hand, was routinely administered to those undergoing painful procedures. Gettysburg surgeons handed out opium pills to men awaiting amputations, and when morphine and chloroform were in short supply, whiskey substituted. Advances in medicine were slow to come, despite the overwhelming availability of military bodies presenting themselves to practitioners. Competition among medical sects and disagreements about licensure created professional mistrust, which served neither patients nor practitioners well. Even though Britain had begun to train nurses in 1860 in the wake of the Crimean War, nurses in the United States did not begin to professionalize until 1870, and most of those detailed to nurse during the war—convalescent men and middle-aged women—had little training other than what domestic life had taught them....