First year of issue.
Ron Guth: By 1891, the old Seated Liberty design (with some modifications over the years) exceeded more than 50 years of service on some denominations. Thus, in 1892, the Mint introduced the new "Barber" design on Dimes, Quarter Dollar, and Half Dollars. The new design's nickname had nothing to do with hair-cutters, but was named after it's designer, Charles E. Barber. As they had done with previous new designs, the public grabbed up the new coins in large quantities, resulting in many high grade coins today. In fact, the 1892 is the second most common Mint State Barber Quarter according to the PCGS Population Report (as of August 2011), with a substantial lead over most other dates in the series. Not surprisingly, the only date with a higher population than the 1892 is the 1916-D, the last of the Barber Quarters (apparently, some collectors thought it, too, was going to be a rarity).
Collectors of today can choose from a range of nice Uncirculkated grades, with the largest populations occurring in the MS-63 and MS-64 grades. MS-65 and MS-66 examples get a little scarcer, but they are not too difficult to find. In MS-67, the population declines rapidly, with less than two dozen examples in PCGS holders. The finest examples appear at the MS-68 level, where the single finest example is a lone PCGS MS-68+ (this remarkably toned example is illustrated above -- it is one of only three PCGS MS-68+ Barber Quarters in the entire series, with none finer).