Why were the american colonies angry with the british government in mid-1700s?

Mostly due to taxation without representation.

Explanation:

While the American colonies were forced to pay many taxes to Britain, they were not allowed any governmental input when it came to parliamentary decisions.

By the 1770’s, Great Britain had established a number of colonies in North America. The American colonists thought of themselves as citizens of Great Britain and subjects of King George III. They were tied to Britain through trade and by the way they were governed. Trade was restricted so the colonies had to rely on Britain for imported goods and supplies. There were no banks and very little money, so colonists used barter and credit to get the things they needed.

Britain also needed money to pay for its war debts. The King and Parliament believed they had the right to tax the colonies. They decided to require several kinds of taxes from the colonists to help pay for the French and Indian War.

Many colonists felt that they should not pay these taxes, because they were passed in England by Parliament, not by their own colonial governments. They protested, saying that these taxes violated their rights as British citizens.

Hope this helps:)