He was born in Hilsbach (Waldhilsbach), Rhenish Palatinate in Bavaria, the son of a forester. He emigrated to Pennsylvania in 1717 and worked at various manual trades, including soapmaking and the manufacture of brass buttons.
He became a British subject in 1724 and joined the Religious Society of Friends (the Quakers) in 1726. He married Catherine Jansen in 1727; they had seven children. With the support of Quaker merchants and political leaders, he set up a glass factory and began buying land and selling it to new immigrants from Germany. His land deals made him one of the richest men in Pennsylvania.
Caspar's brother John (born Johannes) emigrated a decade after Caspar did. While Caspar anglicized his name to "Wistar", John spelled his "Wister". The two each founded prominent Philadelphia-area families, and the difference in spelling persisted.
Caspar Wistar and Catherine Jansen had seven children:
Richard Wistar (died 1781); married Sarah Wyatt. He was a leader in prison reform.
Thomas Waln Wistar
(one other son)
Rebecca Wistar; married Samuel Morris, a figure in the American Revolution.
Margaret Wistar
(two other daughters)
Other descendants include Caspar Wistar, his grandson, and Isaac J. Wistar, figure in the American Civil War and founder of the Wistar Institute.
Sally Wister's Journal