On the East Coast, bear attacks are almost non-existent. The Black Bears around here, while still wild and potentially dangerous, just haven't got much interest in people other than stealing their food, trash, an occasional small pet. Mostly they eat slugs and bugs and berries and the like. Black bears out west are a different matter with a whole different temperament. They eat more meat and are more aggressive. A .357 is probably enough medicine for an Eastern Black. Out west I'd be looking for somethign with more Ooomph.
That said, I've done a pile of hiking in the East, and never even seen a bear in the woods. I've seen a few in or near people's yards, tearing up bird feeders and trash cans and compost piles. When I have heard of bears being a problem for hikers up and down the trail near me, it didn't take much questioning to find out that the folks so "victimized" by theiving bears violated all the rules. They had food in their packs, kept the packs in their tents, and didn't hang their foodbags, toiletries etc. properly in the trees. Bear bag properly and the bears may still get your stuff, but they won't tear up your tent and molest you.
Bottom line: You really don't need a gun for hiking in the east. I also know hikers who've done a LOT of hiking up the Continental Divide and Pacific Crest Trails without ever seeing a dangerous bear. Poison Oak seemed to be a bigger threat to them than even the rattlesnakes. I'd probably take my chances, but then I might also take a compact .45 ACP loaded as hot as possible, and spend the money for either a stainless pistol or a good corrosion resistant coating to minimize my maintenance requirements.