The Everett v. Everett case in 1909 revolved around a dispute over the validity of a will and testament. The plaintiff, Mrs. Mary E. Everett, claimed that her late husband's will was not valid because he was mentally incapacitated at the time it was written due to his excessive use of alcohol and morphine. She also argued that undue influence had been exerted on him by other parties interested in his estate. However, after examining all evidence presented including medical testimonies about Mr.Everett’s mental condition during the period when he wrote his will, as well as considering witnesses who attested to its proper execution under state law requirements for drafting such documents; the Supreme Court ruled against Mrs.Everett’s claims. The court held that there wasn't sufficient proof to establish either claim - neither mental incapacity nor undue influence could be conclusively proven based on available evidences.The court thus upheld the validity of Mr.Everett's last will and testament.

In the dissenting opinion for Everett v. Everett, it was argued that the majority's decision to uphold a lower court ruling denying Mrs. Everett alimony after her divorce from Mr. Everett was incorrect and unjustified by law or precedent. The dissenting justices believed that Mrs. Everett had been unfairly treated in this case due to an overly strict interpretation of a statute requiring proof of adultery for alimony to be granted, despite evidence suggesting she had been subjected to cruel treatment by her husband which should have also justified granting alimony under existing laws at the time.