As a starting point for your research, 70- year-old William Erasmus, was the husband of Catherine Linn. In 1870 they are residing in Columbia County, Ohio. Evidently the wife of their son William T. Erasmus was dead (no wife listed) his daughter Emma is listed as age 13. The father of Catherine (Linn) Erasmus (Dr. George Felix Lynn/Linn) mentioned them in his Hemlock/Bloom Township, Columbia County, Ohio will which was dated 1829 and proved 1836. . Catherine Linn born about 1809 and was the daughter of his second marriage. Catherine and William Erasmus were living in 1838 in Columbia County, Pennsylvania. (Reference Northampton County, Pennsylvania Miscellaneous Record Book 5 Page 103 Easton, Pennsylvania.) The Lynn family came originally from Germany and were in Montgomery, Northampton, Berks and Columbia Counties in Pennsylvania. Check the RootsWeb Family Tree which traces William Erasmus to his father and mother listed as Maria Veronica Rentsheimer etc. to Longswamp, Berks County, Pennsylvania. However, it only gives his wife as Catherine. Hope this helps.