Which British policy convinced many American colonists was hat they should form their own country?

Great Britain did not allow the colonists to participate in government.

American colonists to want to form their own country because Great Britain did not allow them to participate in government. Things got out of control when London implemented a tax on the colonies. This tax put a lot of pressure on the working class and there was a swift movement against the taxes. Eventually, the famous cry 'no taxation without representation' became synonymous with the freedom movement.