To Henry David Thoreau, harmony with nature was his ideal a century
and a half before it became popular to be an environmentalist, and he
retained his fascination with and respect for nature as essential elements of his
lifestyle until his death.

A: ...
B: For Henry David Thoreau, a century and a half before it became popular to
be an environmentalist, harmony with nature was his ideal

C: Henry David Thoreau idealized harmony with nature a century and a half
before to be an environmentalist became popular

D: A century and a half before it became popular to be an environmentalist,
Henry David Thoreau idealized harmony with nature

E: A century and a half before it became popular being an environmentalist,
harmony with nature was ideal to Henry David Thoreau