Final answer:
One key element of the Union victory in the Civil War was splitting Confederate territory by controlling the Mississippi River.
Step-by-step explanation:
One key element of the Union victory in the Civil War was splitting Confederate territory by controlling the Mississippi River. This strategy allowed the Union forces to cut off Confederate supply routes and communication lines, isolating and weakening their forces. The Union was able to gain control of the Mississippi River by capturing key Confederate strongholds such as Vicksburg and New Orleans.
Learn more about Union victory in the Civil War