Find more Brennan 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 1,733 less people named Brennan in the United States — and some of them are likely related to you.
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 25,812 people named Brennan in the 1930 U.S. Census. In 1940, there were 7% less people named Brennan in the United States. What was life like for them?
In 1940, 24,079 people named Brennan were living in the United States. In a snapshot:
As Brennan families continued to grow, they left more tracks on the map: