This picture was taken in 1864, near Brandy Station, Virginia. It shows a Sutler's tent. Sutlers were merchants that followed the army, and sold goods to soldiers. They had a reputation of having pretty bad prices, and in many cases cheated soldiers out of their wages. I guess if you consider the casualty rates of the Civil War, it was hard for a soldier to take a very long term view of things, and I am sure they were an easy mark to anyone selling small life comforts.
It is interesting though, that with these men willing to serve their country, and give their life for the cause, that there would be another group of vultures willing to take advantage of them.