What personal lesson in "American History" has Elena experienced deeply?
Elena, by the end of the story, has experienced something of a coming-of-age in her character, as the way she is treated by Eugene's mother has smashed her dreams irrevocably and also forced her to become aware of racism and discrimination and how it operates in her world. Note how Elena responds to the words that Eugene's mother says to her:
I couldn't move. I just stood there in shock at hearing these things said to me in such a honey-drenched voice. I had never heard an accent like hers, except for Eugene's softer version. It was as if she were singing me a little song.
Although Eugene's mother's voice sounds sweet, it does not mask the cruelty that Elena identifies in the words that she utters, and Elena is forced to experience first hand her own grief, but not for the death of JFK, but for the death of her dreams and innocence, as she realises that she lives in a world where she will be treated differently and judged because of her ethnicity.