PROF. ISAAC DANIEL RUPP was born in East Pennsboro, Cumberland Co., Pa., July 10, 1803, where his paternal grandfather had settled in 1772. In his early life he acquired a fair education, and at the age of twenty began the profession of teaching. In 1827 he located at Harrisburg and opened a private school. He had, at the time of his residence in Harrisburg, access to the archives of the State, and he accumulated from their examination a vast amount of material which he afterward used in writing histories of a number of counties in the State. In 1842 he compiled, and in 1845 published the first “History of Lancaster County,” which was sold by subscription. He translated, wrote and compiled for the press in all about twenty-five books. He died June 1, 1878.
Source: Biographical Annals of Lancaster County, Pennsylvania: Containing Biographical and Genealogical Sketches of Prominent and Representative Citizens and of Many of the Early Settlers (Chicago: J. H. Beers & Co., 1903), p. 149.