The Missouri compromise of 1820 did not have lasting effects, which are the best explanations forth, is a the compromise only applied to the lands of Mexican session so it quickly became irrelevant. B the compromise relied on popular souvenir and public opinion was overwhelming opposed to it. See, the compromise limited. The number of states that could be admitted per year, so it could not be enforced or deed. The compromise only applied to the lands of louisiana purchased and a later law effectively overturned it

C The Compromise did not address the underlying issue of slavery and only temporarily postponed the conflict between the North and the South. This eventually led to the eruption of the Civil War, rendering the Missouri Compromise ineffective.

D The Compromise was seen as a temporary solution to maintain the balance between free and slave states, but as new territories were acquired and settled, the issue of slavery became increasingly contentious. This made the Missouri Compromise irrelevant as it did not provide a long-term solution to the expanding nation.

E The Compromise was ultimately superseded by the Kansas-Nebraska Act of 1854, which allowed popular sovereignty to determine whether or not slavery would be allowed in the newly acquired territories. This act effectively nullified the restrictions imposed by the Missouri Compromise.