"In those days, relatively few people paid income taxes," Mr. Higgs writes. "As late as 1939, fewer than 4 million individual returns were filed, and the filers' total tax bill came to less than $1 billion, or less than 4 percent of their net taxable income."

Beginning in 1940, though, as the government began to mobilize for war, its revenue demands grew enormously. "Federal spending burgeoned from $9 billion in fiscal year 1940 to more than $98 billion in fiscal year 1945. Although the greater part of this spending upsurge was financed by borrowing, huge increases in tax collections also took place," Mr. Higgs notes. "In 1945, 50 million individual income-tax returns were filed, and the filers owed more than $19 billion, or almost 20 times the amount that Americans had coughed up for this tax just five years earlier."

Milton Friedman was an economist at the Treasury during the early part of the war. In his 1998 memoirs, "Two Lucky People," he recalled: "It was clear to all of us at the Treasury, as we set out to multiply the amount of revenue to be collected from the personal income tax, that it would be impossible to do so unless we could develop a system to collect the taxes as the income was earned, not a year later."

The resulting system -- employer withholding -- has remained in effect continuously ever since 1943, even though the war that prompted its creation ended more than 62 years ago. And that system's perpetuation has contributed greatly to nourishing the postwar Leviathan state.

As Charlotte Twight notes in her 2002 book, "Dependent on D.C.," "Withholding is the paramount administrative mechanism that since 1943 has enabled the federal government to collect, without significant protest, sufficient private resources to fund a vastly expanded welfare state."

The Treasury itself acknowledges, in a fact sheet on the history of the U.S. tax system posted at its Web site, that wartime withholding not only "greatly eased the collection of the tax," but "also greatly reduced the taxpayer's awareness of the amount of tax being collected ... which made it easier to raise taxes in the future."

Maybe that helps explain why, in 2005, more than 130 million individual income-tax forms were filed, yielding the federal government $1.108 trillion in revenue, with $787 billion (71 percent) of that amount already having been "painlessly" deducted from wage-earners who never saw it, through the miracle of withholding.

If you want to end the current system in a hurry, just get rid of withholding, requiring all taxes to be paid in full on an actual "tax day."

Then -- as long as you're going that far -- reset "tax day" from April to the first Monday in November, allowing voters to go to the polls freshly reminded of all those things for which they wish to give their elected office-holders their heartfelt thanks.