Old Anderson Family Photographs

Who are these people?

Below is a collection of photos from Mary Ellen Anderson Heine, granddaughter of Emma (photos 2 and 3).
I am looking for information about these photos:  where they were taken, when they were taken, and most importantly, who is in each picture.

Some of the photos have writing on the back, or there is other evidence of the people in them. Photo with complete identification are marked below with green numbers. Photos with some tentative evidence that may help identify them are marked with blue numbers.