In the 1903 U.S. Supreme Court case Leigh v. Green, the dispute centered around a land grant in Florida that was given to Leigh by Congress under an act providing for grants of swamp and overflowed lands to states. The state had previously granted this same land to another party, who later sold it to Green. When Leigh attempted to take possession of the property, he found it occupied by Green and sued for ejectment. The court ruled in favor of Green on two grounds: first, because at the time when Florida made its grant (which predated Congress's action), there were no laws prohibiting such actions; secondly, because even if there had been such laws in place at that time they would not have affected any rights already vested through previous transactions. This decision established important precedents regarding federal-state relations and property law - specifically affirming that Congressional acts cannot retroactively invalidate prior legal agreements or transfers made under state law unless explicitly stated otherwise.

In the dissenting opinion for Leigh v. Green, it was argued that the majority's decision failed to adequately consider and apply principles of equity in their ruling. The dissenting justices believed that there were significant questions regarding whether or not Mr. Leigh had acted in good faith when he purchased property from Mrs. Green, who was allegedly under duress at the time of sale due to her financial circumstances and lack of legal representation. They contended that these factors should have been taken into account by the court before deciding on whether or not to uphold Mr. Leigh’s claim over the property, as they could potentially indicate an abuse of power or undue influence on his part during negotiations with Mrs.Green. The dissent also criticized how evidence related to this issue was handled during trial proceedings; specifically, they felt that certain testimonies which might have supported Mrs.Green’s claims were unjustly excluded from consideration by lower courts based on technicalities rather than merit. Overall, while acknowledging some validity in arguments made by both parties involved in this dispute,the dissenters ultimately concluded that a more thorough examination of all available facts and circumstances surrounding this case would be necessary for delivering a truly fair judgement.