A friend of mine buys homes that are in disrepair and rehabs them. In this case and given the things left behind, it appears that someone just walked away from the home. A smaller coin collection was among the things left behind. In addition to the coins (and medal) pictured below, there were a few rolls of wheat cents, some buffalo nickels and a number of coins from France and Germany.
Great find! I've never seen that sesquicentennial medal before. Judging from the prices on those dimes in the 2x2s, it wasn't put away that long ago. Less than ten or fifteen years, I would guess.
Thanks @lordmarcovan! Medals aren't really my thing, but I hadn't seen it before either. Any information from the Forum dime and medal experts would be appreciated.