What is the act of separating from a nation and becoming independent?

The act of separating from a nation and becoming independent is called secession or declaration of independence.

Explanation:

According to https://en.wikipedia.org/wiki/Secession, secession or declaration of independence is the withdrawal of a group from a larger entity, especially a political entity.

It is a process that begins when a group proclains the act of secession or declaration of independence; it may be a peaceful or violent movement, but its outcome is a new political entity, totally independent.

Increased spending on the military --> increased debt

Increased manufacturing and trade [1939 - 44] --> economy growth of 8%

Increased manufacturing and trade [1941 - 1943] --> economy growth of 17%

Slack of production during the Great Depression --> increased production afterwards as the US economy recovered

Needing more money for the war effort --> the government expanded income tax and added mandatory withholdings from paychecks

Hope this helps!

Bluey :)