Why did Allied troops plan a massive invasion of Western Europe (D - Day) ?

They did that to liberate france from Nazi rule. The Nazis invaded France because of Hitler's desire to capture all of Europe.

Explanation:

workers of lowell mills were greatly benefited for the waltham type of work which was more a paternalist kind, trying to protect the integrity of this little girls coming from small farmers and providing an adequate place of work, this in an effort to avoid the issues of bad place conditions and immorality that the people in bigger industrialized cities of great britain were experimenting.

it's no easy i swear it's hard