You've got family at Ancestry.

Find more Brennen relatives and grow your tree by exploring billions of historical records. Taken every decade since 1790, the U.S. Federal Census can tell you a lot about your family. For example, from 1930 to 1940 there were 642 less people named Brennen in the United States — and some of them are likely related to you.

Start a tree and connect with your family.


Create, build, and explore your family tree.

What if you had a window into the history of your family? With historical records, you do. From home life to career, records help bring your relatives' experiences into focus. There were 2,837 people named Brennen in the 1930 U.S. Census. In 1940, there were 23% less people named Brennen in the United States. What was life like for them?

Picture the past for your ancestors.

In 1940, 2,195 people named Brennen were living in the United States. In a snapshot:

  • 25% were children
  • 2% reported their race as other than white
  • Most common occupation was salesman
  • 2,068 rented out rooms to boarders

Learn where they came from and where they went.

As Brennen families continued to grow, they left more tracks on the map:

  • Most mothers originated from New York
  • 978 were first-generation Americans
  • They most commonly lived in Illinois
  • Most immigrants originated from Ireland