In early life Isaac Fretz followed the vocation of farmer. He owned and lived on the farm in Tinicum Twp. now owned and occupied by Henry F. Myers. He also for a time had teams on the road freighting goods from Philadelphia to Easton, Bethlehem, and Nazareth, with an occasional visit to Pittsburg and other points west. During his absence from home Mar. 4, 1804, his barn was struck by lightning and burned. On this occasion his wife Veronica, displayed heroic energy, in rescuing horses and cattle from the burning building, and undoubtedly would have perished herself in the flames, had she not at last been held back by the neighbors. In spite of all efforts to rescue the cattle from the flames, one horse and fourteen (some say 21) head of cattle perished. In 1815, Isaac built what is now known as the Fretz Valley Mill, on the Tohickon Creek, and in addition to farming operated the mill. During his busy life he succeeded to competency, and accumulated nearly 300 acres of land. He and wives were members of the Mennonite church. He, however, respected all denominations, and would never (without reproof) allow any one in his presence to speak lightly of any church, or church ordinance.