If they've been around since spring, most likely Trumpeter swans. Tundra swans migrate from the tundra and this is a bit early in the year for them. I'll start seeing them show up in numbers the last week of October here in Minnesota. Flock sizes are usually bigger than with trumpeters, I've seen a couple hundred more than once but 50-80 is more common. In the spring most tundra swans migrate northward through the eastern states though last year was an exception. Still, tundra swans would go much further to the north.
Trumpeters were once endangered but they have been successfully introduced everywhere. They will probably become the next Canada goose. I probably have 50+ within a 5 mile radius of my house. Trumpeters tend to migrate as family units to small flocks. I would guess the largest flock I've seen was around 30 birds.
Mute swans are domestic swans gone feral. They are far more aggressive than trumpeters or tundra swans and some states have no restrictions on them. I've seen a few here and there but they seem to disappear in short order. Must not be able to withstand predators very well.