What was one reason why Lincoln pushed for passage of the thirteen amendment

Lincoln recognized that the Emancipation Proclamation would have to be followed by a constitutional amendment in order to guarantee the abolishment of slavery. The 13th amendment was passed at the end of the Civil War before the Southern states had been restored to the Union and should have easily passed the Congress.

i believe your answer is d)

on the morning of  july 21,  1861, general mcdowell ordered the  unionarmy to attack. it was on this hill that  confederate  colonel thomas jackson and his forces held back theunion  troops.