Old Overholt has been available for so long, that I won't go into its background any deeper. What's funny, is the label. Looks like a picture of George Washington, but it's Abraham Overholt – "Father of American distilling".
Old Overholt is surely not "The Forgotten Founding Father" (<- yes, that's my lame movie reference). Like Connosr's own rye specialist @Victor has stated, oxidation makes this rye whiskey much better.
Give it some time, making it less dry and sour. I'm not saying that dryness and sour notes are bad. Old Overholt just needs less of them.
Nose: Stingy and sour rye at first but starts developing into a sweet, sugary rye with time. Little bit of corn and fruits.
Taste: Starts harsh and bitter. Rye and spices. Smoothens a bit, turns into sweet and gingery rye.
Finish: Better than the taste, like sour rye bread with wee spices. Nicely peppery very late in the aftertaste.
Balance: Harsh straight rye whiskey, which becomes decent stuff, when given time.