In 2001 a leftist named Thomas Andrews posted a message to Usenet which accused America's founding fathers of theft, for taking land which belonged either to George III or to native Americans. His purpose was to mock libertarian notions of property
This message has a number of arguments, none of which hold water.
The first suggestion is that George III "owned" the American colonies. It is typical of leftists that they are unable to understand the difference between ownership and government. George III was not the owner of the land, he was the head of state. The idea that no-one owns land in a monarchy is simply based on ignorance and prejudice. I live in the UK, and I own my own home. I pay no rent to the Queen. Why should I? It is my land. The Queen has property of her own but she is not the largest landowner in the UK let alone owner of all the land.
George III no more "owned" the land before the revolution than George Washington became its owner afterwards.
It is from this ignorance about the nature of ownership in an monarchy that this argument stems. The whole confusion between rent - a freely agreed price paid for the use of property - and taxes - a compulsory levy enforced by government violence - stems from this confusion between property and government.
Mr Andrews is on slightly better ground when he claims that the native Americans had, at one point, legitimately owned the land. This flies in the face of the traditional leftist claim that native Americans had no notion of property. Both points could not be factually correct. They could, however, both be wrong, and as it happens they are.
In fact native Americans did have a concept of property. It is a fundament of all societies. They did not have a concept of land ownership. There is a good reason for this. Ownership is a legal structure to determine the use of scarce resources. Prior to colonisation land in North America was not scarce. The first homesteading of the land, therefore, was by the colonists.
Homesteading based on principles of "first use" is not easy to define, but it is very rarely an issue. Most wealth in the world today is not subject to such doubt. No-one had a prior claim on Microsoft prior to Bill Gates creating the company. Some land claims in the past were settled violently, and perhaps not justly. But it is a common principle of law that there is a limitation of possible claims.
It may well be, Mr Andrews, that your ancestors, many years ago, had a claim on the land of the Mull of Kintyre (for example). That does not mean that you have a claim today. The claim has lapsed. Sir Paul McCartney purchased the land in good faith and there is no bar - or none that I know of - to his title.
If Geoge III had owned any land in the colonies - which is possible, for all I know, the Queen owns land in the UK today - and was unjustly denied it, then that is sad, but his descendants have no claim today.