Why would it be harder to supply Union troops as they moved farther south

This question is incomplete, here´s the complete question.

Read the article "North vs. South: Strengths and Weaknesses".

Why would it be harder to supply Union troops as they moved farther south?

The farther into the South the Union troops got made it more difficult to supply them because of the long-distance from their homes.

Explanation:

Furthermore, unlike the north, the south´s troops had the advantage of fighting in their own land, which they knew well, and had better-trained soldiers and experience with guns and horses.

ok whats to talk about were you scared or what?