So, everything changed after the First World War. The men came home. The country was in the middle of a vast expansion. It actually went through a short depression at the end of the war as it reorganized itself and re-employed people. But then in the 1920s, we had a real boom, a boom of factories, a boom in electrifying the country, a boom in building suburbs, a boom in buildings suburban transportation systems, and the beginnings of the electronic age with telephones, and so forth. So, this was a time of really quite big change. In social welfare, we'd had the Russian revolution, and there was a great deal of concern that the C Communist revolution would come to the United States. In 1919, every American City had a daily Communist newspaper, and the labor movement and workers movements and poor peoples movements were very strong. So, there was real fear on the part of those who managed and had control of the economy that the revolution might come here. So, they put on the brakes and slowed down participation and slowed down building systems of support. Part of the reason they were able to do that was because the nation was doing so well. So, technology continued, especially in agriculture. We saw the development of the mechanical harvesters, the development of the cedars to plant crops, the beginnings of Agro chemicals to kill weeds and fertilize crops, and all of this led to continued migration from rural parts to the city parts. So, we had from rural America people moving from the villages and farms into the cities to work in the factories and the expanding technological machine that is America. The agricultural revolution also continued through the South. So, cotton was mechanized, corn was mechanized, other southern products were mechanized. So, there was a need for many fewer agricultural workers. In the meantime, the factories were booming, and so agricultural workers from the South started to move north to the Northern cities, and the Midwestern cities, and the Western cities. This is the first time that there is a significant African diaspora, African American movement to the Northern and Midwestern and western cities. So, we begin to see the growth of black neighborhoods, and we continue to see fairly segregationist policies in the Northern cities. Also as part of this, Puerto Rico which is held as a colony, sees a lot of people moving north and the beginnings of the urban Puerto Rican population. So, the 1920s was a time of social change, but not much time of extension of social support. So, we'll come back and talk about what happens at the end of the 1920s, but before that, in the next lecture, we're going to talk about the major issue of prohibition and at the time.