In 1876, employees at the Philadelphia Mint produced a near-record number of Dimes -- over 11 mllion, second only to the massive mintage of over 12 million in 1853. If all mints are considerd, 1876 was a banner year in which over 30 million Dimes flowed out of Philadelphia, San Francisco, and Carson City. This was a record production that far outstripped any previous year. According to Walter Breen, this reason for this extra production was to replace the 10C Fractional Currency notes still in circulation.
As might be expected, the 1876-P Dime is a very common coin, and one which can be found with ease in top conditions. Gems, even up to MS66, are fairly plentiful (the PCGS CoinFacts Condition Census starts at MS66). In Superb condition (MS67 and better), the 1876 Dime becomes very rare. The finest example appears to be a single NGC MS67+, but the price record belongs to a PCGS MS67.
In 1876, William Barber created a new hub, thus two different reverses appear on 1876 Dimes. On the old, Type 1 reverse, the ribbon on the left side of the reverse has a split end with two points; on the new, Type II reverse, the ribbon on the left side of the reverse comes to a single point.