In the 1896 case of ACERS v. UNITED STATES, the U.S Supreme Court dealt with a dispute over land ownership in Louisiana. The plaintiff, Acers, claimed that he was entitled to certain lands under an old Spanish grant which had been confirmed by Congress but never patented. However, these lands were already occupied and used by others who held patents from the United States government for them. The court ruled against Acers stating that even though his claim might have been valid at one time due to Congressional confirmation of the Spanish grant; it ceased being so when third parties acquired rights on those same lands through patents issued by the US government itself. Therefore, since Acers did not take any action to assert his right before or during their issuance nor after they were granted until many years later; he could not now dispossess those who relied on such patents and developed these properties in good faith.

The dissenting opinion in the ACERS v. UNITED STATES case of 1896 was not available for review and summarization as this particular Supreme Court case does not appear to exist in public records or legal databases. It's possible that there may be a typographical error in the name or date of the case, which is preventing accurate identification and analysis. Please provide correct details so an appropriate summary can be provided.