"Our Flag is There" is a song for the union army. The lyrics talk about Fort Sumter, and how the Union flag waves there. The song talks about Anderson's forces and the battle they had to go through protecting the Fort. They speak of the south as traitors of freedom, and desire to be annihilated. The song was meant to inspire Unionist to protect the precious fort. So the song was trying to build spirit so that people would join the Unions cause in greater numbers.
This Union marching song was basically a battle cry (as the name implies)supporting the north's beliefs in that every one should be free. The lyrics show how patriotic they are to their opinions, and their side of the war. The lyrics say that for every man they lose, they will have a million men replacing them. Again they refer to the south as the traitors. They show that no matter what class you are, you still have to fight for your side in the war. This marching song is meant to raise the soldiers spirits and remind them what they are fighting for.
This song is obviously written for the Union army, because it talks about a blue coat, which is the north's color. The song is about a tired old soldier, who died in the field of battle. He is now going to heaven to get out of his blue and, in the white robe. This is an unknown soldier who no one knows who he is. He died alone with no one by his side, so the union army honor him. This song is used to inspire the Union soldiers to fight for the unknown soldier, and win in his memory.