The Church of Jesus Christ of Latter-Day Saints has released a CD-ROM of data from the 1880 U.S. census, a new tool for people trying to find out about their family roots.

It was no small task. In a news release, the church said it took 17 years and 11.5 million hours of work to create a set that comprises 56 CDs.

The Mormons' vast archives on genealogy are used by people of many religious backgrounds, often simply to fulfill curiosity about their family histories.

But the church has religious reasons for doing such labor-intensive work. Mormons believe there is life after death and that a family can continue in the afterlife if the parents make a promise - called a covenant - in the temple.

Church members can also make covenants on behalf of deceased ancestors, but to do that the members must first be able to identify those who came before them. So the church has a long history of genealogical research and continues to gather records and make them available at its Family History Library in Salt Lake City and at other centers.

The 1880 census database, the latest tool to be released, allows users to use a computer to search for an ancestor's name among the 50,475,366 people enumerated in June 1880 in 38 states and eight territories.

"This new automated census has a far-reaching impact on family history research in the U.S., because it increases access to a highly significant source of information for all families in all parts of the U.S. in 1880," said David Rencher, director of the Family History Library in Salt Lake City.

"Because the 1890 census was destroyed by fire, there is no other federal source like this for 20 years. It makes the 1880 U.S. census of tremendous value."

Further information is available at the Web site www.familysearch.org.