"The Mormon Church is Building a Family Tree of the Entire Human Race" by Christine Kenneally with New Republic, dated 14 Oct 2014.
Here's are some excerpts.
"Even as a large branch of American genealogy sheared off at the turn of the twentieth century into a mad eugenic scheme to reshape the human race, the Mormons got on with their mission to gather and share records. Around that time Mormons whose ancestors had come from Europe could find out about their forebears only by traveling back to their home countries and transcribing whatever information they could find. As a way to assist its members, the church began to send representatives to locate collections of records, copy them all, and bring them back to Utah. In the 1920s the church began recording the genealogical information it had gathered on index cards, and in 1938 it started to make copies on microfilm. Eventually the microfilm was circulated to thousands of Mormon libraries throughout the world. By the 1950s the church elders faced an ever-growing pile of film, and in the wake of the great destruction of records in Germany in World War II, they started to store it safely for posterity inside the Granite Mountain Records Vault.