Complex sentence: Before the six-year era of tall skyscrapers to be built in Atlanta, it was Atlanta's second tallest building from 1982 to 1987, and during that time period, the Westin Peachtree Plaza Hotel was the tallest building in Atlanta.
Split into simpler sentences: Before the six-year era of tall skyscrapers to be built in Atlanta, it was Atlanta's second tallest building from 1982 to 1987. During that time period the Westin Peachtree Plaza Hotel was the tallest building in Atlanta.