Genealogy: Finding Immigration & Naturalization Records

The U.S. is a country built by immigrants. Most residents of the U.S. today are either immigrants or descended from immigrants. Many of them also became naturalized citizens. Below is an overview of what kinds of immigration and naturalization records are available and where to find them.


Immigration is the act of moving from one country to another to permanently reside there.

Good Things to Know:

  • A resident of the British Empire wasn't required to register on a ship if they were traveling from one part of the Empire to another, making records from the Colonial Era spotty
  • Many immigrants from Europe, particularly from Ireland, would travel first to Canada before going to the U.S.
  • The U.S. government did not require passenger ships to file manifests until 1820
  • The National Archives holds records from about 1820-1982 covering numerous ports


Ship Passenger Arrival Records

These records consist of ships' passenger listings. These lists may contain the following information about each passenger:
  • nationality
  • birthplace
  • last known residence
  • occupation
  • who they are going to live with in the U.S.
  • physical description
In general, the more recently the lists were created, the more information will be on those lists .


Naturalization is the legal process of making a person a citizen of a country they were not born in.

Good Things to Know

  • The BPL does not hold or have access to original naturalization records beyond what is available online
  • Naturalization records from before September 27,1906 may held by local (municipal, county, state) courts or Federal courts
  • Naturalization records from after September 27, 1906 are mostly held by the National Archives, with some earlier records held by local courts
  • From 1855 to 1922, most married immigrant women automatically became citizens if their husbands were naturalized, so they would not have their own naturalization records

Types of Records

  • Declaration of Intention: Also called "first papers," this would be filed by someone seeking citizenship after they had resided in the U.S. for at least two years.
  • Petition for Naturalization: Also called "second papers," this would be filed three years after the Declaration of Intention.
  • Certificate of Citizenship: This would be granted if the Petition for Naturalization was approved.

Depending on the year each form was filed, both the Declaration of Intention and the Petition for Naturalization could contain the following information:

  • where and when the person was born
  • details about their arrival to the U.S.
  • names of spouses and children


BPL Resources




  • Ancestry Library Edition - The Immigration & Travel search category includes multiple collections of passenger listings and naturalization records covering Massachusetts, primarily from the 19th century. In Library Use Only.
  • HeritageQuest Online, opens a new window - Provides access to a limited collection of immigration and naturalization records covering the U.S. and various other countries around the world.

Government Resources

Online Records

Online Guides and Articles

Further Reading



Learn More

Join us via Zoom on November 30 at 6:00pm, as professional genealogist Rich Venezia presents a talk called Naturalization Know-How: The Laws and Records of U. S. Citizenship. See more information and register from the calendar event listing