what year did the U.S. mint start minting silver proof coin sets?

Answer 1

Well in 1983 the mint issued the first Prestige proof set. It had the regular proof coins plus a silver Olympic dollar. Those sets were minted up to 1997.Silver proof sets were produced from 1992 through 2007 so far. The also produced a silver Premier silver set from 1992-1998. The packaging was different and they have a lower mintage than the regular silver sets.

Answer 2

Actually pristine sets were first minted in the early 30's. You can find them with mercury dimes but very rare since many were not minted.