I'm a us citizen thru marriage. How do I get proof of citizenship.

  If you have a US passport, that document would be good enough for you to petition for your family members. If not, you would have to apply for a replacement certificate on form I-565 application to replace naturalization/citizenship certificate. Due to the limitations of the Lawyers.com Forums, Alan Lee, Esq.'s (the "Firm") participation in responding to questions posted herein does not constitute legal advice, nor legal representation of the person or entity posting a question. No Attorney/Client relationship is or shall be construed to be created hereby. The information provided herein by the Firm is general, and requires that the poster obtain specific legal advice from an attorney. The poster shall not rely upon the information provided herein as legal advice nor as the basis for making any decisions of legal consequence.