Answer:
Taxation, abuse from soldiers, The Boston Massacre.
Step-by-step explanation:
Taxation: Most everything was taxed by Britain and it was getting expensive for the Colonists.
Abuse from soldiers: Well... they can search you anytime for any reason with no proof or warrant. Also, they can walk up to your home and say I live here now for free. Feed me and take care of me.
The Boston Massacre: This was sort of the last straw for the Colonists. A group of soldiers "blindly" fired into the crowd. This can be disproven but im not going to get into that. They used this public shooting to fuel the revolution and get colonists to fight for their independence.
I hope this helps. Have a good day.