Beautiful Blue Butterfly

I was thrilled to get a picture of this lovely little blue butterfly as it lit on blade of grass. It looked almost unreal as if it were a picture cut from a book. The outside of the wing is whitish and the inside is a periwinkle. I looked on line for some ID and the only one I came up with is a Karner Blue. If that is correct, they are endangered and have a life span of only three and a half days.