This great blog from the Smithsonian about the way containers and grocery stores have changed over the years is very interesting.
http://blog.americanhistory.si.edu/osaycanyousee/2011/10/food-culture.html
However, it seems to focus mainly on the conversion of convenience food in the late 20th century. I think an even more drastic transformation in food shopping happened in the late 19th century when we went from cracker barrels to Uneeda Biscuit individual boxes and when Ivory Soap first advertised itself as 99 44/100th percent pure. There a number of museums with a general store display that help tell this story (a particularly good early one being in Forestville State Park near Spring Valley, Minnesota and find the hands on version at Walnut Grove), but few actual grocery store museums. One that does exist is the Watson Grocery Store in State Center, Iowa.
State Center is in the center of Iowa. Watson Grocery Store was used by the town from 1895 until it closed in the 1981. However, its snapshot is earlier than its closing date. Its owner didn’t like change and while a few things were added, you can definitely still see the early 20th century grocery store there today. I recommend that if you ever get a chance to stop and see it you do.
Information about visiting the Watson Grocery Store:
http://www.silosandsmokestacks.org/attraction/watsons-museum
Information about the historic site including general store in Forestville State Park near Spring Valley, Minnesota (It’s the one in the southeast corner south of Rochester):
http://www.mnhs.org/places/sites/hf/
UPDATED March 3, 2016: I pulled a dead link and swapped another out. I made a small clarity edit. I added the photo of the general store in Historic Forestville. Plus I added my current signature block.
Sarah S. Uthoff is the main force behind Trundlebed Tales striving to bring the History, Mystery, Magic and Imagination of Laura Ingalls Wilder and other greats of children’s literature and history to life for a new generation. Uthoff is a nationally known Laura Ingalls Wilder authority and has presented at five of the Wilder homesites, many conferences and numerous libraries, museums, and events around the Midwest. Attend one of her programs, schedule one yourself, watch her videos, listen to her podcast, and find her on Facebook, Twitter, Google+, LinkedIn, and Academia.edu. Professionally she is a reference librarian at Kirkwood Community College and director of the Oxford (Iowa) Public Library.