What were two main purpose of the declaration

are you talking about the declaration of independence?

if so

The main purpose of America's Declaration of Independence was to explain to foreign nations why the colonies had chosen to separate themselves from Great Britain. The American colonies had already cut most major ties to England, and had established their own congress, currency, army, and post office.

Answer: The Declaration of Independence establishes the values of the United States of America.

Explanation:

It says that "all men are created equal" and have the right to "life, liberty, and the pursuit of happiness." Further, it states the purpose of government is to protect these values.