Where might historical records for diplomats be found? I am specifically searching for personnel files that would contain background information (names of parents, spouse, etc.) My great grandfather was Secretary of Legation to Rio de Janiero in the late 1880's. I assume he must have a personnel file of some sort and had to obtain a passport of some kind. I have searched for passport applications with no luck.The National Archives has provided documents he wrote, his salary, etc., but I am seeking personal information.I know where he was born and that his parents were born in Ireland. The rest has been a dead end. Thanks for any help!