MR. DRISCOLL: The Forgotten Man helped to place FDR into context by focusing on many personal histories of the 1930s, beyond the palace intrigue of Capitol Hill.

These days, whatever collective history we have of the 1920s seems to come from The Great Gatsby, The Untouchables, and TV shows like HBO’s Boardwalk Empire. How badly do people today misremember the decade of the 1920s ?

MS. SHLAES: We really misremember it and then you want to ask why. So Forgotten Man was about the misremembering of the 1930s. Coolidge is about the misremembering of the 1920s.

So the cliches you describe, and they’re fun and amusing, are that it was all a lie or about guns and alcohol, something illegal and contraband, corruption resulting from prohibition. Or it was all a lie; Gatsby wasn’t real wealth. He was an illusion. He was a shimmer in a champagne glass. Right?

So when you go back and look at the ’20s — this is the era of Coolidge, you see a lot of real growth. Things we would envy, we wish we could have, such as employment was often below five percent. When you wanted a job you got one. Wages rose in real terms. Not a lot but consistently. You can go back and look at that, even for unskilled workers. Well, what else — interest rates were pretty low. The budget was in surplus. We didn’t have a deficit. The federal debt was huge from World War I. We were bringing it down reliably.

And in a case people got a car. So you see the inflection points of the Coolidge service in Washington. First there’s a Model T; then comes the Model A. He himself liked Lincoln cars. Actually I think because of the president. So people got cars.

They got electricity. This is very important for households and for women because the drudgery of housework, we can’t even imagine before electricity. Right?

So a lot of things got better.