MN-lucky and others
Just sharing the documentation that you should probably take with you to the interview whether the INS asks or not.
1. Passports
2. For primary applicant , a current empl. letter verifying salary, position and hrs/week and a statement that the position is for an indefinite period.
3. Copies of last 3 yrs tax returns (federal and state)
If spouse also is a derivative beneficiary, then :
4. Completed signed affidavit of support (I think form I-134 or I-34)
5. Documentation to demonstrate that it is a good faith marriage like copies of leases that have both names, bank a/c that have both names, brokerage or mutual fund statements that have both names, copy of marriage cert.
In addition it is better to have copies of your I-140,I-485,birth certs and affidavits if any etc.
INS is always unpredictable. Never know what they may ask for.