Later that year, the Royal Proclamation of 1763 placed a limit upon the westward expansion of the American colonies. The Proclamation aimed to divert colonial expansion to the north (to Nova Scotia) and to the south (Florida). The Proclamation Line did not bother the majority of settled farmers, but it was unpopular with a vocal minority and ultimately contributed to conflict between the colonists and the British government. With the American colonists generally unburdened by British taxes, the government thought it appropriate for them to pay towards the defence of the colonies against native uprisings and the possibility of French incursions. The central issue for the colonists was not the amount of taxes but whether Parliament could levy a tax without American approval, for there were no American seats in Parliament. The Americans protested that like all Englishmen they had rights to "no taxation without representation". In 1765, Grenville introduced the Stamp Act, which levied a stamp duty on every document in the British colonies in North America. Since newspapers were printed on stamped paper, those most affected by the introduction of the duty were the most effective at producing propaganda opposing the tax. Meanwhile, the King had become exasperated at Grenville's attempts to reduce the King's prerogatives, and tried, unsuccessfully, to persuade William Pitt the Elder to accept the office of Prime Minister. After a brief illness, which may have presaged his illnesses to come, George settled on Lord Rockingham to form a ministry, and dismissed Grenville.