Actually, the civil war make their relationship became much worse.
Because of the civil war, the ally has to lose a lot of resources for war supplies and equipment. This led to a situation where the allies no longer able to pay the treaties that they promisd to pay to the Sioux, which eventually ended up in conflict between the two group.
One bad thing tha happened was that the Muslims views on Crusaders and Europeans as a people was drastically worsened. And it's obvious why this happened; they came to their lands and wanted to reclaim them despite not having any real and legitimate claim to these lands.
Preserve the union, end slavery
