You could have found out what it is within a half hour had you used peroxide, actually even after a hour hour in olive oil and some good use of qtips enough detail would show on this coin to ID it, since it appears to have just mostly a crudded over coating, but there is also some corrosion. Once a copper is put in oil, peroxide will not remove the crud unless the oil is removed, which is hard to do..... Don't worry about value, doubt it has anything significant due to the condition. Soaking in olive oil for a long time will remove the crud but why wait for so long.... Flowing Hair term use is not proper usage, if the posters are talking about Draped Bust variety. Flowing Hair type is only a 1793 type of Large Cent. For additional help in IDing in the future on crudded over coins, weight in grams or grains helps and also if it is a thin or thick planchet, so perhaps a edge shot of the coin helps when weight is not possible due to no scale.
Added: Since you are in Mass, I think the appearance does not look like a Coronet type Large Cent, they almost never look that bad and usually show more of a raised rim, so most likely an earlier year Large Cent or Colonial, but lean towards Draped Bust. (But I see no details)
After looking at the photo a bit more, it is very worn down and I believe very little detail might be left, so my advice would be to take a wet qtip, either peroxide wet or olive oil and gently work the area where on your first photo it appears to have letters or numbers at 11-1 oclock position, possibly an S or 5 and other letter or number next to it. That might be enough to at least know what it is. Try the wet qtip on any other area where you in person can possibly see any details, gently working the qtip over such areas, but keep the qtip very wet while doing so and do not rub so hard as to remove the detail, since it just could be corroded detail that is left which would rub off if you are too harsh..........
It has a 26/27mm diameter.
