In what ways did the scope and direction of the civil war change in 1863, and why

The American Civil war changed in 1863 for two reasons.  

Explanation:

First, the union changed the purpose of the struggle to end slavery to the Union. While Lincoln's declaration of liberation actually succeeded in giving freedom to some slaves, it gave African Americans freedom for the Union.

Second, the tide quickly turned against the Confederacy. The success of the Vicksburg campaign provided central control of the Mississippi River, and Lee's defeat at Gatesburg ended the north's invasion effort. The main reason of this war was long term of enslavement of African people in the country.  

what are the choices?

answer; i believe the correct answer is (favorable balance);