What was Pennsylvania's role in the abolitionist movement and the Civil War?

Quakers made up a significant portion of Pennsylvania's population. William Penn, the state's founder, was an English Quaker who had been granted a large piece of land by King Charles II in 1681 to pay off a land debt. Several thousand Quakers left England and followed Penn to the state that he would found. Initially, they were politically active, and they held positions of political influence until deciding that politics often compromised their values, particularly their pacifism.
Instead, they were early devotees of social justice. First, they pursued the protection of Native Americans' rights. Shortly thereafter, they reached an anti-slavery consensus. By the 1780s, slave ownership among Quakers was forbidden. Quakers were among the first abolitionists and participated in the Underground Railroad, harboring slaves until they reached their final destination which, after the passage of the Fugitive Slave Act in 1850, had to be Canada in order to avoid being captured and sent back to the South.
In regard to the Civil War, the most important battle—the Battle of Gettysburg—was fought in Pennsylvania. The battle was decisive, for it resulted in great losses on the Confederate side, as well as General Robert E. Lee's infamous retreat back into Virginia. Lee took his army north with the dual goals of gaining the support of Northern copperheads who were sympathetic to the Confederate cause and winning a battle in the interest of getting the Confederacy recognized by Britain and France.
Instead, 28,000 men were killed—a third of Lee's army. Union losses were not modest either. Union casualties amounted to 23,000. Lee was so dejected that he offered his resignation as general to Confederate president Jefferson Davis, who refused to accept it. The Confederacy went on to win other battles, but Gettysburg, along with Ulysses S. Grant's triumph at the Battle of Vicksburg in Mississippi, set the Union on the course to win the war.
https://www.history.com/topics/american-civil-war/battle-of-gettysburg

https://www.history.com/topics/immigration/history-of-quakerism