"America, 1880-1920
The early 20th century was an era of business expansion and progressive reform in the United States. The progressives, as they called themselves, worked to make American society a better and safer place in which to live. They tried to make big business more responsible through regulations of various kinds. They worked to clean up corrupt city governments, to improve working conditions in factories, and to better living conditions for those who lived in slum areas, a large number of whom were recent immigrants from Southern and Eastern Europe. Many progressives were also concerned with the environment and conservation of resources. This generation of Americans also hoped to make the world a more democratic place. At home, this meant expanding the right to vote to women and a number of election reforms such as the recall, referendum, and direct election of Senators. Abroad, it meant trying to make the world safe for democracy. In 1917, the United States joined Great Britain and France--two democratic nations--in their war against autocratic Germany and Austria-Hungary. Soon after the Great War, the majority of Americans turned away from concern about foreign affairs, adopting an attitude of live and let live.
The 1920s, also known as the "roaring twenties" and as "the new era," were similar to the Progressive Era in that America continued its economic growth and prosperity. The incomes of working people increased along with those of middle class and wealthier Americans. The major growth industry was automobile manufacturing. Americans fell in love with the automobile, which radically changed their way of life. On the other hand, the 1920s saw the decline of many reform activities that had been so widespread after 1900."
The passage above is from what looks like a fasinating page with lots of interesting links from the Library of Congress:
http://memory.loc.gov/learn/features/timeline/progress/progress.html
Of course, since Welles was born in 1915, his early childhhood would have been deeply affected by the tail end of this era; perhaps his sense of deep nostalgia was influenced by the change in society as America became more isolationist, less idealistic and more materialistic and hedonistic in the "Roaring" 20's. The reference in the above passage is also interesting in that it refers to the increased poularity of the automobile at that time, and one surely thinks of the Ambersons:
"Sociologists Robert and Helen Lynd conducted a major study of American society during the 1920s. In 1929, they published their research in a book titled Middletown. "Middletown" was the name used to disguise Muncie, Indiana, the actual place where they conducted their research. One of their findings was that the automobile had transformed the lives of people living in Middletown and, by extension, virtually everywhere else in the United States.
More specifically, the Lynds found that the automobile had such effects as the following: (1) family budgets had changed dramatically; (2) ministers complained that people drove their cars rather than going to church; (3) parents were concerned that their boys and girls were spending too much time together "motoring"; and (4) the car had revolutionized the way people spent their free time."
In addition, Wikepedia also has an interesting page which lists important Progessive Era leaders and intellectuals, among them Teddy and Franklin Roosevelt, Clarence Darrow, Andrew Carnegie, John D. Rockefeller and W.E.B. Dubois:
http://en.wikipedia.org/wiki/Progressive_Era
If we see Welles as a social "Progressive", then we can perhaps understand some of the difficulties he faced in his professional career as the products of his being fashionably or unfashionably liberal throughout his adult life; for example, as Robert Stam has pointed out in his article "Orson Welles, Brazil, and the Power of Blackness", the trouble Welles had with focussing on "non-whites" in It's All True was a large part of the unravelling of that project. The recent rumours that Catherine Benamou has finally decided to publish her long-awaited opus on "It's All True" bodes well for the continuing study of Welles's politics and their influence on his career, as Benamou is both an expert on Latin America, and perhaps the greatest authority on his time in Brazil.