Original: It was a prelude to San Francisco's Summer of Love, which made the Haight-Ashbury district a symbol as the center of an American counterculture and introduced the word 'psychedelic' to suburbia.
Simplified: The Human Be-In led the way to the Summer of Love, which introduced hippie life and the word psychedelic to everyday Americans, and made the Haight-Ashbury area of San Francisco famous as the center of an American counterculture.