Final answer:
There is no explicit mention of Mary Todd Lincoln's beliefs regarding the antislavery amendment; however, Lincoln faced significant political pressure to compromise on slavery, which his wife may have been aware of. Despite this, Lincoln was unwavering in his commitment to the Thirteenth Amendment, partly to honor the sacrifices of black Union soldiers.
Step-by-step explanation:
Abraham Lincoln's wife, Mary Todd Lincoln, may have believed that Lincoln shouldn't push an antislavery amendment due to the divisive nature of the topic during the time and the potential for it to exacerbate tensions between the Union and the Confederacy.
While it is not explicitly mentioned in the provided resources why Lincoln's wife held this belief, it can be inferred that she understood the political landscape and the risks involved with pushing such a controversial agenda. Moreover, political pressures, such as those from conservative Northern Democrats, suggested negotiating peace to end the war without guaranteeing the abolition of slavery.