The Latter-day Saint investment in genealogy is not antiquarian and it is not sentimental. It follows from two doctrines held together. The first is that the ordinances required for the highest degree of glory can be performed by proxy for a person who died without them. The second is that a family can be sealed together permanently. Neither can be done for an ancestor who cannot be identified, so finding names, dates and relationships is a religious duty with a defined purpose.
The apparatus built on that premise is without parallel. The Genealogical Society of Utah was founded in 1894. From 1938 the church began microfilming parish registers, civil registrations, probate records and archives, an effort that eventually reached more than a hundred countries and produced a collection stored since 1965 in the Granite Mountain Records Vault, a facility cut into the granite of Little Cottonwood Canyon southeast of Salt Lake City. Digitisation has since moved most of it online through FamilySearch, which is free to anyone, member or not, and does not require registration with the church. National archives in several countries that could not have afforded to digitise their own holdings did so in partnership with the church on those terms.
The practice runs from the vault down to the ward. Congregations hold family history consultants, temples maintain lists of names awaiting ordinances, and a teenager attending the temple to perform baptisms for the dead is often doing so for names their own family submitted.