a real estate boom

From Chapter 57 of Mark Twain's Life on the Mississippi:

Keokuk was easily recognizable. I lived there in 1857--an extraordinary year there in real-estate matters. The 'boom' was something wonderful. Everybody bought, everybody sold--except widows and preachers; they always hold on; and when the tide ebbs, they get left. Anything in the semblance of a town lot, no matter how situated, was salable, and at a figure which would still have been high if the ground had been sodded with greenbacks.

I the middle of a housing bubble, it must be a dreadful feeling to know that all your mortgageaholic neighbours are getting richer by the minute, while you are being held back by your own boorish sense of prudence.