One possible reason from many is that it's fun to not be human because humans aren't so great to each other. Look into the link between autism and identifying as non-human (there are multiple ways of doing so).

Signed, an autistic being who does not feel emotionally attached to being a human, but is not a furry.

ELI5

Furries are people who enjoy dressing up as or creating characters based on anthropomorphic animals, which are animals that have human-like traits such as walking on two legs, talking, or wearing clothes. These characters might be foxes, wolves, cats, or any other animal but with a personality or appearance that feels human-like.

Some furries create artwork, write stories, or role-play as these characters online, while others might dress up in costumes called "fursuits" to bring their characters to life in the real world. It’s a hobby and a community that’s mostly about creativity, imagination, and expressing yourself through these animal characters.

Is this a community, is this a sexual thing?

It can be either or both. I think for the most part it is community though. For some it starts as one and then expands into the other. For me it really is a lot about self discovery & self expression, SFW & NSFW, and makes me feel more connected to the world.

Or to put it in mature comic form: https://www.ohjoysextoy.com/furry/

Is it an American thing?

No, European here with quite some insight. I think the map in the other post is slightly misleading, as bigger countries like the US have more conventions than smaller countries is kind of obvious.

If you have more questions, feel free to ask 😊 I will do my best to offer my perspective on this.

ofc. Furries are crestive people who enjoy art/litterature/etc. about anthromorphic animals(like werewolves!). A lot of us have our own characters/personas that we create as a avatar of ourselves or to express our creativity and aspects of our identity on a character. This is called a fursona. Now since the only criteria is to enjoy anthromorphic animals(aka furries) there is a lot of range. A lot of us enjoy dressing up as our characters on furcons like people who dress up as their favorite character at comicon. And this interest in furries/anthromorphic amimals/werewolfesque characters can be sexual too for a lot of people. (of course this doesn't have to be) It is just a very big welcoming community of creatives and fans of anthromorphic characters. Hope this helps

re “is it an american thing,” someone else will have to field the rest of your question

Am not a furry, and would also love an explanation. I mean, I ain't knocking whatever it is that gets someone through this world. It can be a very hard, very cruel place, and it dressing up as a electric blue armadillo makes someone happy, and allows them to find people they vibe with, I'm super happy for them. But dagnabbit, I'd really love to understand it. Haha

Also, I know 2 Australian furries and 1 swiss furry, so I'm guessing not an American thing.

Is this a community

Yes. Though you can do it yourself, a lot of furries go to conventions, frequent social media forums and bulletin boards. Just like you would with any other hobby or lifestyle.

is this a sexual thing

Sometimes but not always. The sexual part is a subculture that is part of the larger furry culture.

I don't know if there's any statistics on how large that subculture is either in raw numbers or percentage of all furries, but as an outsider who's picked up info here and there, my guesstimate would be that it's probably a small minority 🤷

Is it an American thing?

Already answered by someone else, but may as well include it here: nope. It's a worldwide thing.

Being openly a furry is probably much more prevalent in culturally liberal (in the original sense of the word rather than the political one) countries than ones that strictly enforce specific cultural norms. And Japan, probably 🤷