Tropicopter....
I feel compelled to correct one of your misconceptions about the origins of the USA....we did not flee the old country...by force of arms, we defeated your army and navy and won our independence from an abusive government. As a direct result of that defeat and surrender of forces, your government was forced to withdraw its forces and return them to other areas of the empire.
Many of our early settlers had indeed fled from religious persecution in Europe and settled in the colonies. That is why we have within our Bill of Rights, an article(amendment) that prohibits a "state sponsored or state created religion".
Many of our states have laws that are derived from the English common law and actually still have cites to those laws although it is becoming more common for the modern law to be less tied to those conventions. Also, the laws in Louisana owe more to the French influence of that region than to the English common law. The laws in the Spanish or Mexican areas of the US are also derived in great part from those cultures as well.
One of the philosophical changes is the "Victim's Rights" movement which is slowly changing the concept of violent crime being a violation of the peace and dignity of the state (read Crown) and making it a crime against the person of the victim whereas the old common law made it a property crime against the Crown. (as during the days when serfs were considered property of the Crown).