In the case of Pierre Choteau, Senior v. Marguerite, a Woman of Colour (1838), the Supreme Court was asked to decide whether or not a woman born into slavery in Missouri could be emancipated by her master and become free. The plaintiff argued that under Missouri law, slaves were considered property and thus could not be freed without permission from their owner; however, the defendant argued that she had been promised freedom by her former master before his death and should therefore be recognized as a free person. After considering both sides' arguments, the court ultimately ruled in favor of Marguerite's emancipation on grounds that it would have been unjust for her to remain enslaved after being promised freedom by her former master. This ruling set an important precedent for future cases involving slave emancipation in Missouri and other states across America at this time.

In the case of Pierre Choteau, Senior v. Marguerite, a woman of color, the Supreme Court was asked to decide whether or not a person born in Missouri before it became part of the United States could be considered an American citizen and thus entitled to certain rights under state law. The majority opinion held that since Missouri had been acquired by treaty from France prior to its admission into the Union as a state, those born there were not citizens and therefore did not have any legal protection under U.S. laws at that time. However, Justice McLean dissented from this decision arguing that while Congress may have intended for those living in newly acquired territories to remain subject only to their former government until such time as they were incorporated into states within the Union; nevertheless he believed individuals should still be afforded some degree of protection regardless of their place or date of birth so long as they resided within U.S territory when it was annexed by treaty with another nation or admitted into union with other states already existing therein . He further argued that if persons residing in these areas are denied all civil rights then “the most odious tyranny” would result which is contrary both “to reason and justice”