Hello: We live in Industry, Illinois, located in west central Illinois, near the Mississippi River. I have worked on our family name for over 25 years and have lots of information on the various spellings. I have found 120 different spellings, but we are undoubtedly all distantly related. We can trace our name back to seven early men in Frederick County, Maryland in the 1770s. I am descended from Christian. You are most likely descended from Henry, although some of Thomas' descendants also use the ISENAGLE spelling.
If you are interested, I can share with you what I know about the Isenagles in particular. That spelling is probably the least common today, but there are still several families around the country. Nice to hear from you.
Roger Icenogle