What did the Declaration of Independence do?

The Declaration of Independence announced and declared the independence of the United States from Great Britain. This is an official USCIS civics question; acceptable answers include that it 'declared our independence (from Great Britain)' or 'said that the United States is free (from Great Britain).' Adopted on July 4, 1776, and primarily authored by Thomas Jefferson, it set out the colonies' reasons for separating from British rule. It did not end slavery, create the Supreme Court, or establish Congress — those came later through other documents and events. Its core purpose was declaring independence.