My oldest daughter is 15. Being the oldest of my four daughters, she was the first to have an American Girl doll.  I have seen first hand, the benefits that these dolls provide to today's girls.
I'm a homeschooling mom so I'm always looking for a fun way to sneak in a school lesson here and there. American Girl dolls have helped me teach over and over again and they have helped my girls make that "mental connection" needed for real learning.  Its that light bulb moment that every parent and teacher can see on a child's face.
Nearly 6 years after the first AG doll entered our home, we have several 18 inch members of our family. However, we have many more books than we have dolls.
Trips to the local library always include a search down "the American Girl aisle" for any book that we haven't read yet. We're fortunate that our library has many of the older books that we can't find in stores any longer. 
Every time period we have studied has included references to an American Girl Doll.  Even my younger girls can reference a doll when I present a time period to them.  Any reference to World War II brings up Molly. Mention the Wild West and some one will surly mention Kirsten.  Civil War or slavery lessons always include Addy. 
I have found that a doll is worth a thousand words. 
So much is shown by these wonderfully costumed dolls and their stories. So much can be seen by the primitive furniture and accessories of Kirsten or the beautiful ritzy style of Samantha and her belongings.  So many things are learned just by seeing. Our eyes absorb more than our ears.
We leave a mental implant in our children's mind when we can engage multiple senses. Its been scientifically proven. 
As I've gotten older, I have noticed how easily I forget things. I often walk into a room and forget why I'm there. I forget to return phone calls. I forget to pull the chicken from the freezer in the morning so it will be thawed in time for dinner.  (This always results in take out for dinner!)
Because of this weakness, I have become more acutely aware of things that I remember.  Things from my childhood like my favorite doll, a particular event or a special food that my grandmother used to make.  I should have forgotten these things yet their memories are forever in my mind. Why? Why can I remember things from so long ago and yet forget to take out the chicken?  Well, its because my senses were engaged.
The more senses we engage, the better we remember.
I can remember at the age of 3 and 4, having a large rag doll. I had gotten it for Christmas from my parents.  Although I don't remember the very first time that I ripped it, I can remember my grandmother stitching it up for me many times. She and my grandfather would come over for dinner and while we ate, I would tell her about the rip in my doll. While she would tell me that she knew my dolly had been injured, she would reach into her purse and pull out the sewing kit that she had brought with her. I would run and get my doll. I would hold dolly to comfort her while grandma would stitch her back up and tell me a story about the doll she had when she was young. 
My senses were engaged. I was hearing her calm, comforting voice soothe my worries. I was watching her put a thimble on her finger and thread the needle.  I was touching my favorite doll and feeling the comfort of her plush body and yarn hair.  The entire event was an emotional experience for the little girl that was afraid her favorite doll was beyond repair.  It is forever engraved in my mind.  Some, well I won't tell you how many decades later, I can still picture it as if it happened yesterday. It created an imprint, because my senses were engaged.
Learning is not memorization.  Learning is just that, learning.  Discover something new, that you didn't know before and now you know it.  Its not countless hours of learning facts or figures or spelling words.  Its learning an idea and then being able to think independently to come up with your own solutions.
Do some research on spelling bee training.  You'll soon realize that while it is impossible to learn to spell every single word in the English language, children still study for spelling bees......not in mundane memorization but they learn rules instead.  Rules of spelling will teach them things like "drop the y, add ies" or "i before e, except after c" or even how spelling is formatted based the root language that the word has come from.
My girls are more attentive when I present a fictional story of a girl their age and the coordinating time period. It will teach them at their level, about how they might have lived in that same time period. They will engage their senses and emotions to create an imprint in their minds. They will learn enough to be able to draw their own conclusion and determine their own solutions.
Here's an example from our "classroom."  We have spent some time learning about Felicity and the Colonial Time Period.  We have done all kinds of activities from tea parties to crafts to a play about the Boston Tea Party.  I ask my 7 year old, "Did Felicity have a microwave?" She looks at me like I'm crazy and quickly answers, "No. Of course not."  How does she know?  Because our brains have these amazing "filing cabinets" in them. When we present our children with a fictional yet historically accurate story they are completely engaged.  They learn so much more than what is said in the story. They are able to pair what is in the story with information already in their "filing cabinets" and come up with a solution to an off the wall question like the microwave question.  Thus, we raise in independent thinker.  Someone who is able to draw on life's lessons and experiences to be a problem solver and a leader. They're not reciting facts and being limited to what they have memorized but they are THINKING.
Any spelling bee winner will tell you that at some point along their quest for the trophy, they encountered a word that they had not memorized, perhaps never heard before yet they were able to figure out how to spell it and move on to the next round. How? Because they learned the rules, the basic information that helped them to think independently and solve the problem.  Have you ever watched a spelling bee? One at a State or National level? Those children amaze me. If they are unsure of a word, they will rely on the ethnicity of the word and the definition or the number of syllables and probably many more factors that this homeschooling mother is yet to discover.
I have found that for our family's classroom, the Charlotte Mason teaching method works best.  Charlotte Mason believed in exposing children to great literature as a means for leaning every subject, except math and penmanship.  A controversial method, even for today, it is based on the "filing cabinet" system of our brains.  Sure I was skeptical when I first encountered her methods but her thought, "Trust the process." continued to ring through my mind.  Her methods call for using "live books" to teach every subject, even every topic.  When you want to teach about the Pilgrims, get good literature about that specific topic.  When you want to teach about birds, expose your children to books specifically about birds.  Use writing that the author is passionate about, rather than dry, boring text books.  Her idea is that they will learn spelling and grammar by being exposed to as much literature as possible. The process works. My girls are living proof.
If we can combine some sort of hands on learning to the wonderful stories, we've done even better and likely created an imprint that will last a lifetime.  A simple role play with their dolls can do so much for learning.
As a mom, my goal is not just to teach the history but the values that go along with the time period. Its about preserving a way of thinking and an innocence that has been lost through the years.  That, however is a topic for another day.
So for today's question....I want to know if your daughters have ever referred to an American Girl doll based on history or a social situation. Tell me your family's story and what these dolls have done for your girls.