What documents are required for a US family-based visa application?

Passport, birth certificate, marriage certificate (if applicable), proof of relationship, and sponsor's income documents.

Valid passport, birth/marriage certificates, proof of relationship (photos, letters), sponsor's Form I-864 (Affidavit of Support), and financial documents.

Passport, proof of relationship (birth/marriage certificates), sponsor's proof of income (tax returns), and Form I-864.