America was isolationist- everyone wanted to stay out of European military affairs at all costs and they felt that the League of Nations would drag the US into unnecessary affairs.
World War II was the war fought to bring "essential human" freedoms. However, in America, many minority groups did not have the essential freedoms they were fighting overseas for.
For example, black men served in the US military and gained new economic opportunities in factories during World War II. These men were vital to the war effort. However, they still lacked the same freedom in the US in comparison to white citizens. Many black citizens were stopped from voting, attending the same school as white citizens, etc.
This was also true for Japanese American citizens. Thousands of Japanese-American citizens were put into internment camps by the US government after the attack on Pearl Harbor. This limited the freedom of these citizens even though they did not commit any crimes.
Answer:
I can't see the picture you're talking about, so it's going to be kind of difficult because I don't know what exactly you're talking about.
The answer :
Since the weapon technology was basically equal, it was an advantage for the Confederates.