The Mint Act of February 12, 1873 - the infamous Crime of '73 - was an omnibus bill that included a weight increase for the Dime. The actual increase was infinitesimal, the new weight standard being 2.50 grams as opposed to 2.49 grams. Apparently, the change in 1873 was made in an effort to make the weight of the Dime conform more closely to the metric system. The Mint decided that an indentifying feature was needed to distinguish those coins struck after February 12 from those struck before that date. Harkening back to 1853, officials once again decided to place arrows at both sides of the date.
The Arrows, Legend Obverse Seated Dime series lasted for just two years: 1873 and 1874. Most business strikes of this type were delivered in the Philadelphia Mint, but the Carson City and San Francisco facilities also contributed limited numbers of coins in both years. Survivors of these mintmarked deliveries are scarce-to-rare in all grades (CC-mint examples are exceedingly so), while those of the P-mint issues are very scarce in Mint State from the standpoint of market availability.