The English who in the seventeenth and eighteenth centuries inhabited those colonies that would later become the United States shared a common political vocabulary with the English in England. Steeped as they were in the English political language, these colonials failed to observe that their experience in America had given the words a significance quite different from that accepted by the English with whom they debated; in fact, they claimed that they were more loyal to the English political tradition than were the English in England. In many respects the political institutions of England were reproduced in these American colonies. By the middle of eighteenth century, all of these colonies except four were headed by Royal Governors appointed by the King and perceived as bearing a relation to the people of the colony similar to that of the King to the English people. Moreover, each of these colonies enjoyed a representative assembly, which was consciously modeled, in powers and practices, after the English Parliament. In both England and these colonies, only property holders could vote. Nevertheless, though English and colonial institutions were structurally similar, attitudes toward those institutions differed. For example, English legal development from the early seventeenth century had been moving steadily toward the absolute power of Parliament. The most unmistakable sign of this tendency was the legal assertion that the King was subject to the law. Together with this resolute denial of the absolute right of kings went the assertion that Parliament was unlimited in its power: it could change even the Constitution by its ordinary acts of legislation. By the eighteenth century the English had accepted the idea that the parliamentary representatives of the people were omnipotent. The citizens of these colonies did not look upon the English Parliament with such fond eyes, nor did they concede that their own assemblies possessed such wide powers. There were good historical reasons for this. To the English the word "constitution" meant the whole body of law and legal custom formulated since the beginning of the kingdom, whereas to these colonials a constitution was a specific written document, enumerating specific powers. This distinction in meaning can be traced to the fact that the foundations of government in the various colonies were written charters granted by the Crown. These express authorizations to govern were tangible, definite things. Over the years these colonial had often repaired to the charters to justify themselves in the struggle against tyrannical governors or officials of the Crown. More than a century of government under written constitutions convinced these colonists of the necessity for and efficacy of protecting their liberties against governmental encroachment by explicitly defining all governmental powers in a document.