Americans tend to be interested in presidential tax returns partly because presidents tend to be wealthy. But our tradition of tax privacy shields the returns of wealthy Americans from prying eyes.

That wasn’t always the case. In 1924 Congress passed a tax law that included what was known as a “Peeping Tom” provision. It required that the names of all taxpayers, and the amount of tax they paid, be made public. Unbelievably, the information was posted on the walls at regional tax offices.

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