Henry McAllister Jr. was born in 1836 in Brandywine, New Castle County, Delaware, to Henry McAllister Sr., a first generation American.
His mother, Hannah Askew, was the daughter of a family that had been in America from Colonial times, and who were members of the Religious Society of Friends.
By 1840 the family had moved to Darby, Delaware County, Pennsylvania, very close to Philadelphia. Henry Jr. soon had two sisters who lived out their lives in Philadelphia and remained faithful to the Quaker faith.
After his schooling at the Darby Friends School and a brief career in merchandising, Henry Jr. joined the Union Army at the start of the Civil War.
Quakers had been the first abolitionists in America, and many of the more liberal branch of the faith decided to fight to free the slaves.
During these years he served under General William Jackson Palmer, also a Quaker born in 1836 in Kent County, Delaware. Palmer had also moved to Philadelphia as a young man.
During the war, Henry served in the Fifteenth Pennsylvania Cavalry and rose to the rank of Major.
He proved himself to be a brave and successful leader. Some items from his war experience still remain in the Museum.