Key Date Coins to the Silver Washington Series
The 1932 D is considered the number one key coin to the silver Washington Quarter series. Although there were slightly more Denver coins produced than San Francisco, less of the Denver coins survived in high grades making the 32 D highly sought after. Even in lower more heavily circulated grades this coin has a value of over $60
Even in the lower, heavily circulated grades these coins are still worth around $50
Semi Key Dates
Unlike a lot of the other coin series from this era and earlier, it's not really as much the mintage numbers that drive certain coins to being considered semi key dates, but their survival in the higher grades. What is similar, hoever, is that they are all either Denver or San Francisco coins. Just like the Lincoln Cent, not many were minted, and these early coins were used heavily, especially during the depression era in an area of the country that was farther away and didn't see as much coinage from the eastern part of the US which would have brought the Philadelphia issues in to mix with the Denver and San Francisco coins.
To a lesser extent these coins, too are semi key dates
Top 10 Lowest Mintages