What an event the Calvin Coolidge Presidential Foundation hosted in the city to mark the introduction by the United States Mint of the “Coolidge Dollar.” The base-metal coin is the latest in the Mint’s presidential series. The evening was cheerful and non-partisan; the dollar, after all, is a concern for all parties. The speaker, journalist James Grant, asked whether anyone knew the etymology of the phrase “sound money.” He then held up the genuine article, a silver dollar, and dropped it on the podium. The ringing of l’argent filled the room with a merry reminder of the constitutional principles.

Our Second Congress, the first to use the Constitution’s coinage power, defined the dollar as 371 ¼ grains of silver, or a 15th as much gold. This opened a century long debate over bimetallism. It was settled in the presidential election of 1896, when the Democrats put up William Jennings Bryan. He stood for free silver and vowed he would not be crucified on a cross of gold (he ended up hawking swamp land in Florida). The Republicans put up William McKinley, who stood for defining the dollar in gold. It proved it to be the winning formula.

The Gold Standard Act became the supreme law of the land in 1900. It defined the dollar as a 20.67th of an ounce of gold. That, for the record, is the dollar in the Coolidge years. It was the legal definition of the dollar when, a century ago, the Congress established the Federal Reserve. It happens that the House balked at the idea of a central bank, but it finally agreed to create one after language was put into the law saying that nothing in the act would authorize an end to the convertibility of the dollar into gold at the legislated rate.

War rattled the international gold standard, but it is to the great credit of America that it held fast — including in the 1920s, when others fell away. Coolidge enabled this triumph by cutting the budget, leaving it smaller than when he had entered office. The 30th president, we are reminded by the Web site thegoldstandardnow.org, records in his autobiography that he came to an understanding of the gold standard in the very 1896 presidential campaign in which Bryan stood for inflation. Coolidge was in Northampton, and a Democrat had endorsed Bryan in a column in a local paper.

“This I answered in one of the city papers,” Coolidge later wrote. “When I was home [in New Hampshire] that summer I took part in a small neighborhood debate in which I supported the gold standard.” He said that “the study I put on this subject well repaid me.” And, we’d add, the country. How wonderful that one of the programs of the foundation that now honors the 30th president — and is chaired by our own Amity Shlaes — gathers high school students at Coolidge’s birthplace at Plymouth Notch, Vermont, for a series of debates of the kind in which our 30th president honed his understanding of political economy.