Is a copy of a birth certificate and divorce papers acceptable to USCIS or do I need originals?
You should never send original supporting evidence to the USCIS, unless they specifically ask for it. Always send a photocopy. The USCIS won't return you your original supporting documents back either, so be prepared to never see them again if you send those in. You will need to send some original "wet signature" documents, but in terms of supporting documents like birth certificates, death certificates, divorce decrees, etc., only send copies. This also goes for RapidVisa customers. Don't send RapidVisa any original supporting items unless you are prepared for those to be never returned to you. This goes for fiance visas, spousal visas, adjustment of status and all other petition types.
We have seen a couple cases where the consular officer at the US Embassy has requested originals, which you would bring with you to the Embassy and those have been returned to the owners. But keep in mind, these were only cases when specifically requested.