These coins—a one-year type—bear Mexico City’s mintmark, and many were indeed struck there (c.10,799,150), but large numbers were also coined at the American mints in Philadelphia (25,000,000), Denver (17,000,850), and San Francisco (18,000,000).
The 1935 American coinage for Mexico is a real oddity. Mexico has rarely needed much help meeting its own coinage requirements, and what help it has needed it has usually been more comfortable getting from European sources. In fact, the only previous instance of American coining help was in 1906-07 as the new “ESTADOS UNIDOS” coinage was getting established. {The deliveries Included the only New Orleans coinage for another country.) Not until 1949 would an American mint again strike Mexican coins—and those were intended for the Nationalist Chinese.
But back to 1935 and these 50-centavo pieces. The American coinage reflects the much-improved Mexican-U.S. relationship of the time, and suggests too that Mexico needed a lot of 50-centavo coins very quickly. The denomination hadn’t been produced since 1925—so supply was likely tight anyway—and the country’s improving economy was putting pressure on coin supplies at the very moment high silver prices were further reducing their availability.
But the emergency was short-lived, and Mexico’s long tradition of good silver coins quickly reasserted itself. Very quickly reasserted itself—I have read that these 1935 50-centavo pieces were demonetized on 28 August 1936. (This particular example certainly supports that date.)
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