Why were so many americans anxious about the economic future of the nation at the conclusion of world war ii? why did these fears prove groundless?

Perhaps it's all about the destruction that the nation had to face after the war. It did not take long before America recovered from this phase. The transition of some industries to military armament manufacture caught the economy from total lost.

according to this text from the preamble to the declaration, who gives men their unalienable rights?

their creator