What were the two main causes of the Amercian revolution?

There were several, all stemming from a change in the mercantile system that allowed Britain to let the colonies grow and prosper at their own rate.

1) The French and Indian War, for which the British sought to recover their expenses

2) The Proclamation of 1763 that restricted expansion into the Ohio Valley (Native lands)

3) The refusal to grant the colonies representation in Parliament

4) Oppressive or punitive taxes: Tea Act, Stamp Act, Intolerable Acts

5) Increasingly oppressive governance: the Boston Massacre was one notable incident