I also descend from John L. Erwin, his son Oscar, his son Steve, his daughter Gracie Erwin Porter, her son Don Porter, then myself JC Porter.
We have John L. Erwin;s father as John Armstrong Erwin. Some of us descendants of John L. Erwin started a myfamily website about a year ago for the John L. Erwin family. We have posted quite a bit of information and pictures on that site. Would be glad to send you an invitation to the site, if you send me your email address. Mine is JCPorter@indy.rr.com