What the names of two rock legends that passed away in the early 70s?

 Janis Joplin and Jim Morrison

Explanation:  Janis Joplin (1943 - 1970), American rock and blues singer, distinctly sharp and distinctive voice, with extraordinary vocal abilities. Especially popular during the hippie movement during the 60's of the 20th century. One of the most famous versions of the work she performed was Summertime.

Jim Morrison (1943 - 1971), an American singer, poet and leader of the band The Doors. Known for its performances and an extremely melancholic voice, according to critics, one of the most authentic pop icons of modern music of the 20th century.

nothing certain is known about what happened, but it seems that the country declined gradually, perhaps due to bad government, or, more likely, due to a series of bad harvests, which resulted in widespread and recurrent famine.

in griswold v. connecticut (1965), the supreme court ruled that a state's ban on the use of contraceptives violated the right to marital privacy.