Answer:
The main purpose of the expert of the document from the Declaration of Independence is to announce the decision of the colonies to sever their ties to England.
Step-by-step explanation:
As writer can convey any message they want the reader to receive, it is their unique talent. So in the Declaration of Independence the writer has written with the main purpose of announcing the decisions of the colonies.
The writer says that it becomes necessary for one people to dissolve the political bands which have connected them with another.