The public is able to request copies of the DAR records. You can contact the DAR offices at 1-800-449-1776 and they can connect you to the research library people. It may cost you a bit per page and for the research and mailing costs.
You will need to have his ancestor number, as shown on his membership page on the DAR Sticker.
When members apply, they are supposed to provide both the children of the Patriot along with their dates of birth, death and any spouse information including dates of marriage.