On April 2, the National Archives and Records administration began to release data from the 1940 U.S. Census.
Last month, volunteers finished uploading all of the South Dakota records to the Internet.
"I think it's safe to say that families and folks interested in their family history are kind of like kids in a candy store," said Paul Nauta, spokesperson for the 1940 U.S. Census Community Project.
Available for free since June 14, the records contain such information as the names and ages of all family members, occupations, place of residence and whether they owned or rented the place in which they were living.
One question unique to the 1940 census was where individuals had been living five years previous.
"(That) is really interesting, because there was a lot of migration during that decade because of the Great Depression," Nauta said. "People began moving to find work, so the federal government was interested to see where people were, where they had migrated from."
Once all information pertaining to a state has been uploaded, documents are searchable by name, as well.
All of the records have been uploaded through the efforts from thousands of volunteers across the country.
"As an online project, we were hoping to get around 100,000 volunteers to help us with that project so we could complete it by the end of the year," Nauta said. "We've actually had close to 200,000 volunteers, and we continue to get about 1,000 a day logging on new to the cause to help out with it."
As of last month, those volunteers already passed the halfway mark, indexing 80 million of the approximately 132 million names listed.
By the beginning of this week, 30 states have been made completely available online.
"It's technology-driven, it's all Web-based, so anyone that wants to volunteer just logs on at The1940Census.com, clicks the link to be a volunteer, and it downloads the indexing software on your desktop," Nauta said. "There's a tutorial that shows you how to work it and everything, and you choose a state that's remaining that's of interest to you."
For example, if a volunteer chooses New York, a page from the 1940 New York Census will be downloaded for them.
They must then follow the instructions until they have typed the entire document, Nauta said.
"Two indexers are doing the exact same document unbeknownst to each other," he said. "Two volunteers are getting the same page to index. If every bit of their entries do not match up 100 percent, the discrepancies are then electronically sent to an arbitrator, who will look at the entries … and make a judgment call as to what the correct transcription was.
"The result is, it is processed and the index is put online for free," he said.
Besides just looking at the data itself, users also have the option of clicking an image icon that allows them to view the actual document.
"You can discover all kinds of things," Nauta said. "My mother-in-law is alive and in the census – about 25 percent of Americans are alive today that were in the census – and so I called her and told her I was looking at her. …
"She was totally fascinated, and I was able to go own the street on that census page and ask her if she knew any of the other families, calling out the names of the children who were about her age," he said. "And she knew all of them – a lot of them she had totally forgotten about. It was a fun experience for her to be able to kind of walk down memory lane that way."
The 1940 U.S. Census Community Project is a joint initiative between the National Archives and Records Administration, Archives.com, FamilySearch.org, findmypast.com, ProQuest and other genealogy organizations.
To volunteer or to browse the records, visit The1940Census.com.