It should be noted that only those persons are listed on the SSI Death Index when SSI has issued a death benefit toa qualifying,aureviving spouse. There are 171 William Eldridges on the latest index. IBut you have to have either his date of death, or date of birth in order to tie someone into the index. If you know where they were living in 1900, you might try the 1900 census index for that state. Don't give up hope. He's out there. Find them.