What were the social structures of the indus valley and egyptian society?

The answer to your question is: Little is known in detail about the societal structure of the ancient Indus Valley inhabitants, because their writings have not been deciphered as of 2014. However, archaeologists have made many discoveries that suggest Indus society was highly egalitarian with a centralized government. Statues and art from that time suggest a high degree of equality with regional leaders forming a central authority.

The changes to agriculture in the united states since 1900 is that increased mechanization has increased food production, thereby increasing the need for labor. there has been an increased need for higher speeds of food production due the fact that the population in the united states continues to rise.