Explain how the Treaty of Guadalupe Hidalgo changed the United States' southern border.

the congress realized that action had to be.

they had many gains 1 one freedom for slaves the major cause of the civil war is that the   north wanted freedom for slaves but the south didn; t creaitng the civil war

another gain they have is poltiical influence

poltiical influence is a big thing everywhere even now peoplle are always trying to get the head up in poltics thats what they did by giving the republicians a good name for freeing slaves