Which is the best description of the significance of the union victory in the siege of vicksburg?
a) the union victory at vicksburg resulted in northern control of the mississippi river.
b) the union victory at vicksburg stopped the confederate army's invasion into pennsylvania..
c) the union victory at vicksburg resulted in the immediate surrender of the confederacy and the end of the war.
d) the union victory at vicksburg resulted in overwhelming support for president lincoln in the election of 1860.