In 1861 the U.S. Government started building a 4,500 bed military hospital at the corner of Clark Park near 44th Street and Baltimore Avenue. Rows of frame ward buildings stretched northwest to around 46th and Pine. After the battle of Gettysburg, tents for the wounded were set up on the grounds bounded by 43rd and 44th streets and Baltimore and Osage Avenues.
At first the hospital was called West Philadelphia General Hospital, but it was later renamed for Brig. Gen. Richard S. Satterlee, the army’s medical purveyor.
This was the largest Army hospital in the United States. Many local doctors and civilians, including the 25 Sisters of Charity, volunteered to work there. Sick and wounded were brought here from the battlefield. Some wounded were floated on rafts along the Mill Creek, which formerly ran by the site, to the hospital from a ferry landing at 42nd and the Schuylkill River. Horses pulled wagons up the slope of what is now the 4300 block of Larchwood Ave. A military band played daily concerts and music for dress parades and dirges for the dead. More than 60,000 servicemen were treated at Satterlee.
The Satterlee Hospital officially closed on August 3, 1865.
The Philadelphia Archdiocesan Historical Research Center (PAHRC) has a page devoted to the nurses who worked at Satterlee Hospital.
The Wikipedia page on Satterlee Hospital.
In June, 1916, another historical monument was placed in Clark Park. A large stone memorial from Devil’s Den at Gettysburg Battlefield was placed in the park to commemorate the “services of the patriotic men and women” who administered the wounded soldiers in the tents of Satterlee Hospital which also once stood nearby.