U.S. Document Legalization
As a result of Poland's ratification of the Convention Abolishing the Requirement of Legalization for Foreign Public Documents, entered into force on August 14, 2005, the Polish Consular Offices in the United States no longer carry out the legalization of most public documents executed in the United States for legal use in Poland.
Instead of legalization of documents, The Convention introduced a unified certificate or "Apostille," which is attached to the documents. Documents certified in such a way may be provided directly to the proper authorities, offices and institutions in Poland.
Detailed information about which documents require what kind of certification and how the certification can be provided can be found here.