This Washington Post article tells the story of how the word Hispanic (rather than Latino, for example) came into use by the Feds. Unsurprisingly, it has to do with a committee of bureaucrats in the Department of Health and Human Services, in 1975. It’s very much worth reading. I am reminded of a speech Richard Rodriguez (author of "Hunger of Memory") last year sometime (I saw it on C-Span) in which he said something like this, by way of mocking such nomenclatures: I flew to Bolivia once, got off the plane, went to the nearest local and said to him, "Would you be kind enough to take me to a Hispanic, I’ve never met one. He didn’t know what I was talking about."