Why didn't the Declaration of Independence really give colonists their independence from England?

It did but to answer the question the Declaration of Independence had to be recognized by other countries. Britain did recognize it. That's why we don't have a British flag in our flag today.

Explanation:

they thoght they were going to nuke each other

on april 6, 1917, the u.s. joined its allies--britain, france, and russia--to fight in world war i. under the command of major general john j. pershing, more than 2 million u.s. soldiers fought on battlefields in france.