In the case of Mangan, Administrator of Pillow v. United States (1920), the Supreme Court ruled on a matter concerning inheritance tax law. The decedent, Mr. Pillow, had transferred his property to his wife before he died with an agreement that she would provide him with income for life and upon her death or remarriage, the remaining property would go to their children. After Mr. Pillow's death, Mrs. Pillow sold some properties and used part of it for personal expenses while investing the rest in bonds which were later seized by government authorities during World War I due to their German origin. The issue was whether these transactions constituted taxable transfers under federal estate tax laws or if they should be considered as merely providing support for Mrs.Pillow as per her husband’s wishes without any transfer of ownership rights over those assets taking place. The Supreme Court held that such arrangements did constitute taxable transfers because there was a change in beneficial ownership from Mr.Pillow to Mrs.Pillow even though legal title remained with him until his death.The court also found that seizure by government didn't exempt them from taxation since they still formed part of estate left behind by deceased.

The dissenting opinion in the case of Mangan, Administrator of Pillow v. United States argued that the majority's decision to uphold a tax on an inheritance left by a deceased American citizen who lived and died abroad was unjustified. The dissenters believed that this interpretation expanded the scope of U.S. taxation powers beyond what is constitutionally permissible, as it effectively allowed for taxation without representation - something fundamentally at odds with American principles. They contended that since the decedent had no property or assets within U.S jurisdiction at his time of death, there should be no basis for imposing an estate tax upon him under federal law. Furthermore, they pointed out inconsistencies between this ruling and previous court decisions regarding similar matters which further underscored their disagreement with the majority's judgment.