Taxation without representation, the colonists were taxed by the British without the Colonists own government being consulted. Another reason was the that the British did not allow the Colonists to move into the newly aquired area of the northwest region(Ohio, Kentucky etc.), because the British promised the area to the Native Americans. And may I note the Colonists actually considered themselves to be British.
The invasions of Germanic groups led to a series of negative changes . Three effects of the Germanic invasions were halt on trade. Transportation of goods became unsafe. Less people were educated, and Europe no longer had one spoken language, unable to be understood by all.