Some by asking for loans from other countries or they also raised taxes to their citizens to pay for it ( which is what America did)
Answer:
Social change can cause conflict within and between societies. Social change can cause a cultural lag which leades to conflict. A main conflict is between youth and parent, which is a result of social change.
During the 20th century there was war. This includes World War I. The wars would cause poverty in familes due to the high demand of food and supplies to soldiers overseas. This led to other families fighting for survival.
White expansion. War between Indians and the whites was very common because the whites seemingly had quite an appetite for the Indian land. Indians struggle to contain this aggressive expansion led to war with hope to reduce American settlement and expansion.