Witnesses?
Your question doesn't really have all the information necessary to have an accurate answer.
The Stamp Act, Tea Act and Intolerable Acts were put into place without the consent of the colonists. This proved that Britain was not treating them as citizens, but merely as servants to their mother country.
The Americans realized that Britain was not going to stop enacting laws in the colonies this way, and they knew that secession was inevitable.
Answer:
Declare war
Explanation:
Only Congress can declare war