Most major differences:
Role of Government
The role that government played in the American colonies was much smaller than in Britain itself. A rallying cry for American independence was “no taxation without representation!” Well, guess what? The people back home in Britain had representation, all right, so they were taxed on a wide variety of things, although income tax wouldn’t arise until after 1800. On the other hand, taxes in the American colonies were virtually nonexistent. However, levels of government services were not correspondingly better in Britain, as most tax money went into subsidizing businesses such as the East India Company and into fighting Britain’s wars.
Economy
The American colonies were much better off economically in 1770 than Great Britain was. Without taxation and with the benefit of free trade within the vast British Empire, the North American colonies had the highest per capita standard of living in the world. However, the drawback to free trade was that they were kept in a largely agrarian economy, as their function in the Empire was to provide raw materials to Britain’s newly-formed industry. As a result, by 1800, Britain was far ahead of the new US in industry, and that industry lead was what made independence so daunting for the colonists.
Major similarities:
Social structure
The social structure in the colonies varied widely by region, but situations in each colony were analogous to the social structure in parts of England. The South resembled the English countryside, in which landed gentry were at the top, while propertyless whites and slaves were at the bottom. In urban centers like Boston and New York, the new middle class of merchants, doctors, bankers, and lawyers dominated the social scene. Rural New England was similar to some areas in Scotland and England in which yeoman farmers owned land independently of aristocracy.
Culture
The culture and education of the American colonies was essentially British culture. Colonists and British spoke the same languages, read the same books, danced the same dances, ate similar food, and had virtually identical worldviews. Religious denominations were more diverse in America, but social and cultural priorities were largely consistent between the two.
There are other similarities and differences, but these are the biggest ones I can think of at the moment. Essentially, the colonists and the British were the same people, but with different economic situations and political expectations.
