The 1940 U.S. Census revealed that Missouri had 3.8 million residents, there were 1.8 million Kansans, and Kansas City, Missouri, was home to 400,000 people.

This year the National Archives and Records Administration opened the 1940 U.S. Census records to great fanfare, creating a valuable resource for historians and genealogists.

The National Archives’ Lori Cox-Paul, using some notable area residents as examples, explains how the census can facilitate the search for your ancestors. Cox-Paul has worked for the National Archives since 2004.