Naturalization processes, first created by the U.S. Congress in 1790, has been a judicial function ever since, and applicants for citizenship are required to follow a regular judicial process, including application and petition to the court, court action, and right of appeal. Applicants whose petitions for citizenship are granted are also required to take an oath of allegiance to the U.S. All of these actions are recorded in the record volumes of the appropriate county court.
Record books from the Clay County Courthouse recording naturalization information from 1872 to 1954 including Declarations of Intention and petitions for citizenship by immigrants living in Clay County; applications to take the Oath of Allegiance to the U.S.; and copies of Final Citizenship Papers. The record books are indexed in a general index volume, arranged by family name. The records books were microfilmed by the Minnesota Historical Society.