There was a real-life Friedrich Bhaer. In fact, Louisa May Alcott wanted to marry him and even start a school with him. This man appears in literal disguises in all of her novels. He is Friedrich in Little Women, Mac in Rose in Bloom and David in Work and many more. Henry and Louisa shared a deep friendship, was it more than friendship? In Little Women Jo's and Friedrich's age gap is 16 years. It is the same age difference as between Henry and Louisa.
One of the models for Jo and Friedrich might be Louisa's friend Elizabeth and her husband. Her life was surprisingly similar to the book Jo. She wasn't a writer, but there are parallels. Based on what I have found, her marriage with her lawyer husband was a happy one. She was devoted to the educational work and in the same way, as Jo does, she promoted co-education, for both male and female students. She became a dean of the university. Same way as Jo who becomes the matriarch of the Bhaer Academy in "Jo´s Boys"..
There is a very compelling case to be made that Henry David Thoreau was the real-life Friedrich Bhaer. Louisa once called her friend Emerson "The God of my idolatry" but it was Henry who merited her lifelong affection. The ties between Henry and the Alcotts are more extensive than one might expect. From the time when the Alcotts moved to Concord in March 1840 until Henry's passing in 1862. He was a frequent guest in the Alcott´s home taking tea or dinner with the family. Bronson who admired the young man's intellect often visited him in his hut at Walden Pond. If the connection between Henry and the Alcotts was strong, the connection between Louisa and Henry was even stronger
