Where did most political machines arise and receive the most support at the turn of the century?

Most political machines rose and received the most support from areas with large immigrant populations. Many machines were created in cities to serve the immigrants to the United States in the late 19th century. They regarded machines as a vehicle for political enfranchisement (having the right or privilege especially in electoral votes). Machine workers helped win elections by emerging the most voters on election day. 

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.