I came across this coin and picked it up for $10. I really didn't know much about the mintage, but just liked the design. Anyone know the key dates for the 50 cent pieces?
When your looking for them, they are all key pieces! (1903-1921): Generally the 1905-S is hard to come by in higher grades and all of them in mint state grades can get pricey minus the 1920 and 1921 (1944-1945): These can be found often and up to around MS64 can be had fairly easily. MS65 and above can be difficult to locate though. But I have just started on this series so these are my observations in a short amount of time.
1904 is the key date for circulating silver issues from Philadelphia. 1906-S pesos are also keys, and are quite rare and often faked. 1906 and 1908 Philadelphia mint issues are also very rare, issued only as proofs.