: Wealth was concentrated; the top 5% of Americans held more income than the bottom 60%.

: Easy access to credit allowed ordinary citizens to invest in the stock market, often through risky "buying on margin". The Hidden Fault Lines

: Much of the era's prosperity was fueled by credit that consumers could not truly afford. The Great Crash and Global Collapse

: Innovations like the assembly line made cars, radios, and household appliances affordable for the first time.