I am lucky enough to have had the opportunity to both learn and mull over the story that is photo history. An image's relevance modifies with time - some work that once appeared remarkable now seems dated or overly-stylized. Other work that once seemed remote and irrelevant now appears intuitive, personal, and delightful. All things change when looked at through the lens of time.
Throughout my years of enjoying and considering photos, Robert Frank has been remarkable from beginning to end. His imagery is beautiful yet cutting, composed while remaining emotionally involved. He poured his intensity and his questions into his images. I can feel this while looking at a reproduction, to the point of them being too much too see at times. They are raw and open, and for this I love them. Above is one of my favorites photos ever. 
The good news is that SFMoMA must agree with me, as they have begun a Frank retrospective! This includes the many (hard to find) movies that Frank made as well as original prints from the Americas. Go Go Go! I will be there too.