Cannonball

Following the Battle of Gettysburg in early July 1863, perhaps as many as 21,000 wounded soldiers remained in Gettysburg for medical treatment, according to Licensed Battlefield Guide Phil Lechak. As soon as they were stable enough for a train ride, they were transported from the various temporary field hospitals (often in barns, sheds, stables, private houses, churches, and schools) to the Gettysburg train station on Carlisle Street. Trains left regularly for Hanover Junction, and from there the men were taken to New York City, Baltimore, Harrisburg or York.
Here is a record of the initial shipments of Union soldiers to the York U.S. Army Hospital on Penn Commons:

Once Herman Haupt and the U.S. Military Railroad finished enough repairs to burned bridges and wrecked rails to allow trains to pass from Gettysburg to Hanover Junction, the Union army began shipping wounded soldiers from both armies from Gettysburg, initially to Baltimore. In fact, from July 7 until July 16, every trainload of injured men that arrived at Hanover Junction was eventually sent down the Northern Central Railway to Baltimore, where they were taken to various hospitals around town. On July 17, the first trainload headed for New York City.
At 9:00 a.m. on July 17, U.S. Army trains # 80 and 47 left for Hanover Junction with a different final destination – York, Pa. They carried more than 200 wounded men who soon became patients at the town’s army hospital.
The following afternoon, at 3 p.m. on the 18th, another train (#125) left bound for York, again with only Union soldiers. On the 19th, two more trains left at 9:00. Train # 107 carried more Federals from the Army of the Potomac. However, train # 25 had a much different set of passengers, Confederate soldiers from the Army of Northern Virginia, perhaps including a few from Jubal Early’s Division that had occupied York only days before. That same afternoon, train # 107 carried more Yankees to York’s hospital, which was rapidly filling up (keep in mind that a couple hundred invalids from earlier battles were still being treated by the pair of military surgeons on staff in York).
The shipments were not finished. York’s workload would grow in the next few days. The regular 9:00 dual trains from Gettysburg (on the 20th they were trains # 257 and # 141) steamed into York’s depot and unloaded more suffering patients. However, by now, the majority of the wounded were being sent to New York City, although Harrisburg and Baltimore were also still receiving regular shipments.
For the next few days, only one additional trainload arrived in York, this one train # 54 which departed Gettysburg at 4:00 p.m. on July 21. Dr. Henry Palmer had his hands full, supplemented by volunteers from the town’s medical corps. More than 11,000 wounded men had left Gettysburg via Hanover Junction between July 7 and July 22. Another 2,000 where shipped from the train station at Littlestown through Hanover and Hanover Junction to Baltimore. Others departed from Westminster, Maryland, for Baltimore, bypassing the busy aid station at Hanover Junction.
Some of those wounded men taken to York so long ago in military trains are still in the city, buried in the Prospect Hill Cemetery after succumbing to their injuries despite Palmer and his staff’s best efforts.
Rest in peace, Gettysburg warriors, rest in peace.