Originally imposed as a populist method of preventing massive amounts of "inherited wealth" which was seen as corrupting and evil. Expanded to the point that a farmer can't pass the farm on to children due to large amount of cash demanded by the Fedgov at transfer, so the farm is sold to a large corporation and the kids get a part of the sale price. Lots of people use trusts to pass property down one or even two generations, including the very wealthy against whom the tax was originally directed. The small business owner who dies without putting the business into a trust with the kids gets bought out upon death, part of the money to the Fedgov, the rest to the kids. "Down with the wealthy!"