I'm sad about the damage, because I really love this vintage photo. I asked my grandma who these people were, also about lots of people in other photos, but she said a lot of the people she didn't know because they were part of my grandpa's side of the family before she got to know him. And grandpa's been dead a long time now. So they remain anonymous for now. Unless I find something in the future to let me know. After all, only recently did I find all of these vintage photos.
Updated info: After examining other vintage family photos and identifications, I know that the woman standing on the left is my great-grandmother, so the rest of the kids are probably her siblings, and the other two adults are probably my great-great-grandfather, and the old woman might be my great-great-great-grandmother (the man's mother?). But still, the only one I know for sure is great-grandmother. She died in the early 1970s. Anyway, they were all from Missouri.
NOTE: Larger resolution upload - 11 July 2011