John H. Dietrich was born on 14 January 1878, in a farmhouse near Chambersburg, in Franklin County, Pennsylvania. His parents were German-Swiss whose ancestors had immigrated to that isolated part of the state in 1710. They were members of the Reformed Church, which originated from the efforts of the Swiss reformer, Ulrich Zwingli. Dietrich was named after the local minister, Jacob Hassler, who later encouraged him to become a minister. At age fifteen, he entered Mercersburg Academy, which was four miles from his home. Because his family did not have the money for room and board so he could live on campus, he had to walk the round trip to the Academy each day. He also had to compensate his parents for his tuition fees by performing odd jobs around the farm. Even with these hardships, he completed the four-year course in three years and graduated valedictorian of his class in 1896.
From The Dictionary of Modern American Philosophers in Oxford Reference.