What does constitute a historically underrepresented background to get a grant? Does that mean that grandparent might have been poor but not had access to a grant because they're not considered underrepresented according to RC criteria?

Don’t be obtuse. You know it’s either race or sex based. If they were open to poor Indian or Appalachian men they’d mention that kind of thing explicitly.

> historically underrepresented background.

Is that similar to Affirmative Action -based grants?