In Ripley v. United States, the Supreme Court ruled on a dispute involving land patents and their validity under U.S. law. The case involved a man named Ripley who had purchased lands in California that were originally granted to Mexico before it became part of the United States. After purchasing these lands, he discovered they were already patented by another party under U.S. law and sued for compensation from the government arguing that his purchase was made in good faith based on Mexican laws at that time which allowed such sales. The court held against Ripley stating that once land has been patented under U.S law, any previous claims or rights are extinguished unless specifically preserved by treaty provisions when territories change hands between nations - as happened with Mexico ceding California to the US after war ended in 1848. Therefore, even though Mr.Ripley may have bought those lands legally according to Mexican laws then applicable; since they were later patented by someone else under American jurisdiction without any specific preservation of prior rights mentioned during transfer of territory from Mexico to America – his claim was invalid.

In the dissenting opinion for Ripley v. United States, it was argued that the majority's decision to deny Mr. Ripley his claim against the government was incorrect. The dissenting justices believed that Mr. Ripley had a valid contract with the U.S Government and he performed his duties as per this agreement, hence he should be compensated accordingly. They disagreed with the majority’s interpretation of “extra work” in relation to contracts and asserted that any additional tasks completed by an individual beyond what is explicitly stated in their contract constitutes extra work deserving of compensation. Furthermore, they contended that if there were ambiguities or uncertainties about terms within a contract, these should not automatically disadvantage one party—in this case Mr.Ripley— but rather such issues ought to be resolved equitably between both parties involved.