Ron Guth: In 1908, the motto "IN GOD WE TRUST" was restored to the reverse of the $10 Indian, correcting the deliberate omission on the 1907 and early 1908 issues. The new version was struck intermittently until 1933, at which time the U.S. went off the gold standard and gold coins were discontinued. Many of the previously struck coins were melted down; in some cases (such as the 1933), great rarities were created. Many $10 Indians were shipped overseas, where they remained as reserves in European banks until bullion dealers began repatriating them in the 1970s. Strike quality varies throughout the series, with the S-Mint issues of 1916 and 1920 often displaying weakness on the high points. Proofs were issued from 1909 to 1915; these display a non-brilliant finish that ranges from satiny to a grainy, sandblast finish. All Proofs are rare and many suffer from careless preservation.
This is one of the most popular series of American coins and high-grade examples are eagerly sought-after by enthusiastic collectors.