Yes, other documents may be accepted, but they need to contain your son's name, his date of birth, and his biological parents' names. We also like it to have a recent photo, but we can accept it without a photo if it has enough information to verify his identity.
Is there any way my son can legally work without DHS authorization?
Yes, you can apply for an Individual Taxpayer ID Number for your son at the IRS. You can visit your local IRS office or call them toll free at 1-800-TAXFORM and request a Form W-7A for Taxpayer ID Number for Pending U.S. adoptions.
Is there any way I can prove his U.S. immigration status?