The Sanford v. Sanford case of 1890 revolved around a dispute over the will and estate of Lewis Sanford, who had passed away in New York. His widow, Mrs. Mary E. Sanford, contested the validity of his will which left most assets to his brother John F.A. Stanford and other relatives rather than her or their children as per state law at that time for intestate succession (when there is no valid will). The Supreme Court ruled in favor of Mrs. Mary E.Sanford stating that Mr.Lewis's last testament was not legally binding because it did not comply with the requirements set by New York State law regarding witnessing a will signing process - specifically having two witnesses present simultaneously during its execution.

The Sanford v. Sanford case does not have a publicly available dissenting opinion recorded in the legal archives, which suggests that the court's decision may have been unanimous or any dissenting justices did not choose to write a separate opinion. Therefore, it is impossible to provide a summary of such an opinion for this particular case from 1890.