There was no land available in the British Isles and Western Europe by the 16th century. Every acre was owned by someone, either a private individual or by the crown. The traditions and laws of primogeniture and entail meant that an estate should be passed on intact to the oldest son. But to John Locke, private property arose from natural law and existed prior to the creation of civil society. The right to property did not depend on heredity but was to be a right of all citizens. If you study 18th century concepts of property, you will find that they believed that there should not be an attitude of laissez-faire, ie, "let people do as they want". You will not find, in any writings of the founders or of the political and economic thinkers that influenced the founders of this nation, any passage that affirms that an individual, within civil society, has all possession rights to his property as did the hereditary Aristocracies of Europe. In fact, it was often quite the opposite, as described by James Madison, who wrote that his party hated hereditary power and are offended by every public measure that does not apeal to the general interest of the community.
Repealing the estate tax, as the neocons desire, would enrich the heirs of America's millionaires and billionaires while hurting families who struggle to make ends meet. Many desire a strengthening of the estate tax. Warren Buffet defends the estate tax as playing a "critical role" in promoting economic growth. Repealing the tax "would be a terrible mistake," the equivalent of "choosing the 2020 Olympic team by picking the eldest sons of gold-medal winners in the 2000 Olympics."
The rich stick their millions in places like offshore hedge funds leaving us all to pick up the burden of paying their taxes. Family farmers and small business owners are unfairly stuck with paying estate taxes that the richest can avoid. The poor get poorer and the rich find loopholes.