This interesting piece of history has been unearthed by Smygo:

Robert Shea & Robert Anton Wilson:

“There was private money long before there was government money. The first revolutionary (or reformist) use of this idea, as a check against galloping usury and high interest rates, was the foundation of “Banks of Piety” by the Dominican order of the Catholic Church in the late middle ages. (See Tawney, _Religion and the Rise of Capitalism_.) The Dominicans, having discovered that preaching against usury did not deter the usurer, founded their own banks and provided loans without interest; this “ethical competition” (as Josiah Warren later called it) drove the commercial banks out of the areas where the Dominicans practiced it. Similar private currency, loaned at a low rate of interest (but not at no interest), was provided by Scots banks until the British government, acting on behalf of the monopoly of the Bank of England, stopped this exercise of free enterprise. (See Muellen, _Free Banking_.) The same idea was tried successfully in the American colonies before the Revolution, and again was suppressed by the British government, which some heretical historians regard as a more direct cause of the American Revolution than the taxes mentioned in most schoolbooks. (See Ezra Pound, _Impact_, and additional sources cited therein.)

During the nineteenth century many anarchists and individualists attempted to issue low-interest or no-interest private currencies. _Mutual Banking_, by Colonel William Greene, and _True Civilization_, by Josiah Warren, are records of two such attempts, by their instigators. Lysander Spooner, an anarchist who was also a constitutional lawyer, argued at length that Congress had no authority to suppress such private currencies (see his _Our Financiers: Their Ignorance, Usurpations and Frauds_). A general overview of such efforts at free enterprise, soon crushed by the Capitalist State, is given by James M. Martin in his _Men Against the State_, and by Rudolph Rocker in _Pioneers of American Freedom_ (an ironic title, since his pioneers all lost their major battles). Lawrence Labadie, of Suffern, N.Y., has collected (but not yet published) records of 1,000 such experiments.”