In the mid-20th century, banks were far less concentrated than they are today
"In the mid-20th century, banks were far less concentrated than they are today, when the five biggest — JPMorgan Chase, Bank of America, Citigroup, Wells Fargo and Goldman Sachs — dominate the industry, with combined assets amounting to more than half of the nation’s economy."
Source: Gar Alperovitz, "Wall Street is Too Big to Regulate," The New York Times, July 22, 2012. Accessed July 27, 2012. http://www.nytimes.com/2012/07/23/opinion/banks-that-are-too-big-to-regu... [verified 4/22/14]