The Tea Act of 1773 heightened tensions in the American colonies by enforcing taxation without representation and giving the British East India Company a monopoly on tea sales. Colonists viewed this as an infringement on their rights, leading to significant unrest. The act prompted the Boston Tea Party, where colonists protested by dumping tea into the harbor, symbolizing their fight against oppression and rallying more support for independence. Overall, the Tea Act became a catalyst for the growing revolutionary sentiment in the colonies.