When our ancestors came to America, they didn’t just leave behind their homes and belongings; they also left behind entire lives. Immigration and naturalization records in our genealogy research can help us reconnect with those early journeys. As genealogists, these records can add depth and help answer some of the most important questions in a family tree.
In this post, I’ll walk you through how these records work, where to find them, and how to use them to discover more about your ancestors. Whether you’re just starting out or trying to fill in missing pieces, immigration and naturalization records are rich with clues.
One of the most frequently asked questions I receive as a professional genealogist is how to find my immigrant ancestor. Everyone wants to know how their family came to the United States and where they came from. Let’s see how these record sets can help you find those answers.
Immigration vs Emigration
The first thing to note when talking about this subject is the difference between immigration and emigration.
Immigration is the act of moving TO a new country. Emigration is the act of moving FROM a country. Example: William Dunahoo, my 3x great-grandfather, immigrated to the United States, but he emigrated from Ireland.
What Are Immigration Records?
Immigration records document the arrival of people into a new country. In the U.S., these include ship passenger lists, border crossing records, and sometimes visa applications. Officials created these records when someone entered the country, either at a seaport, airport, or land border.
Most of our ancestors will be arriving by ship, so we’ll concentrate on that type of record. Keep in mind that the early passenger lists have far less information than later ones.
Examples:
This is the 1843 passenger list for my 3x great-grandparents, John and Mary Astle. They’re the only ancestors I’ve found who arrived through New York City. At the time, officials spelled their last name Austall. Since they came from England and spoke with an English accent, that’s probably how the clerk heard and recorded it.
The list itself is very simple—it only includes each passenger’s name, age, sex, occupation, country of origin, and destination country.
After 1893, passenger lists included many more details, including full name, age, sex, occupation, nationality, last permanent residence, name and address of a relative from where the person came, final destination, who paid for passage, height, weight, place of birth, and more.
IMPORTANT TIP: These later passenger lists have two pages, so be sure to look for both.
These details help paint a fuller picture of an immigrant’s life. You’ll see family patterns, economic clues, and even reasons for coming to the U.S.
Where to Find Immigration Records
Many immigration records are available online. The biggest collections can be found on the following websites:
When you search, try different name spellings. Names were often misspelled (or at least not spelled how you think they were). Look for others who traveled with your ancestor. People migrated together, and they may be listed that way on the manifest.
You can also search by port of arrival. Common ports include:
- New York (Castle Garden 1855-1890 and Ellis Island 1892-1924)
- Boston
- Baltimore
- Philadelphia
- Savannah
- New Orleans
- San Francisco (for Asian immigrants)
Each port kept its own records, so be flexible and cast a wide net.
For more information about how to use these records in your genealogy research, check out this article from FamilySearch: United States Emigration and Immigration.
Also, read my blog post, I Found My Immigrant Ancestor – Now What?
What Are Naturalization Records?
Naturalization is the process of becoming a U.S. citizen. These records are separate from immigration records. They offer details about a person’s life after arrival. Naturalization records can tell you when and where someone lived, their birth details, and even who witnessed their application.
The process changed over time, but usually involved:
- Declaration of Intent (First Papers) – Said the immigrant wanted to become a citizen. Often includes birthdate, birthplace, and arrival information.
- Petition for Naturalization (Second Papers) – Usually filed a few years later. Includes address, occupation, spouse’s name, children’s names and birthdates, and sometimes a photograph.
- Certificate of Naturalization – The final step. A formal certificate was issued to the new citizen.
Older naturalization records (before 1906) may not have much detail. After 1906, the federal government standardized the process, and records became more detailed and reliable.
Where to Find Naturalization Records
These records can be found at different levels: local courts, state archives, and federal agencies. Start with:
- Ancestry and FamilySearch – Great for indexed collections.
- National Archives – Holds many federal naturalization records, especially after 1906.
- USCIS Genealogy Program – If your ancestor became a citizen after 1906, this is another option. You can request records directly from them.
If your ancestor never became a citizen, there might still be records of their intent. Or, you may find immigration documents marked “Alien – Not a U.S. citizen.” Don’t skip those as they still tell a story and could contain valuable information.
How to Use These Records in Your Genealogy Research
Start with what you know and work backward. If you know your ancestor was naturalized, try to find the date or location. That can help you locate the correct courthouse or archive.
Compare immigration records to census data. Many census years asked if someone was naturalized. In the 1900, 1910, 1920, and 1930 censuses, look for citizenship questions like:
- “Year of Immigration”
- “Naturalized or Alien”
- “Year of Naturalization”
That helps narrow your search window. The years of immigration may vary depending on the informant. Also, the further away you get from the immigration year, the more likely the memory of the event faded.
Once you find an immigration record, study it carefully. Is there a destination listed? That can lead you to city directories, land records, or church records in that location. Was a family member named as the contact? That could be your next research subject.
These records aren’t just paperwork, they’re clues to finding out more!
Other Ways to Immigrate
Not everyone immigrated through major ports. Many Canadians and Mexicans entered by land. If your ancestor lived near the border, try looking for:
- U.S.–Canada Border Crossings (1895–1960s)
- U.S.–Mexico Border Crossings (1903–1950s)
Also, remember that some people changed their names, either legally or informally. Perhaps they wanted a more Americanized name or one that was easier to pronounce. But it is a myth that clerks or immigration officials changed your ancestors’ names at the border. You might find different versions of a name across different records. Take notes and make connections carefully.
Another issue? Some women and children were listed under a husband or father’s name, with only initials or first names. Try looking at full families or nearby entries for context.
Finally
Immigration and naturalization records can help us understand the courage and persistence of our ancestors. They’re more than just facts and forms; they’re real-life stories waiting to be uncovered.
If you haven’t explored these records yet, make it your next research step. Start with one ancestor. Use what you already know to guide you. And don’t be afraid to get creative. Sometimes the best discoveries come when you follow small clues.
And if you get stuck? That’s normal. Research takes time, and it’s okay to ask for help.
Genealogy tip: Especially with later immigration records, it’s important to take your time and comb the document for all available clues. Stay organized by writing down everything you find. Correlate new information and make a note where you want to go next in your genealogy journey.
I hope this post gives you a strong starting point. If you’d like help finding your immigrant ancestor, give me a call. The first 30 minutes are free. Click below to get started.
