If someone loves history, how (or where) would he find more people with the same interests?

Most area’s have an historical society, by town, county/region, or state. That’s one way to find people, and then meet people that are interested in the areas he is.

And one of the wonders of the internet is finding people with similar interests. Go to Meet Up dot com to find if there is a group, or he could even start one in his area.

Search on line for “American History study group”. Who know what you might find.

@zenvelo Has some good suggestions.
He might also find a group that does historical re-enactments of battles, like the Civil War battles that many people participate in, depending on the part of the country you live in.

I live in a historic gold rush town and we have all sorts of historical events with authentic costumes and set ups in our state park. Re-enactments of the gold rush era days.

He could check out Meet-up groups (online) in his area of interest.

Perhaps there is a history club near the local college around your area? How old is he? Has he thought about becoming a history major?

Reenactment or ‘living history’ groups. If he lives in any of the former Confederate states, there will definitely be a living history group somewhere in the state and they do battle reenactments; if he lives in New England, there are Revolutionary War living history groups. In the west, there are some 49’ers or cowboy/Indians reenactors. In Montana there’s something called a Mountain Men rendezvous. Most of the living history type of events are also accompanied by festivals or weekend events where you can go to watch if you don’t necessarily want to participate. Also, check out Renaissance Festivals—some are serious about accuracy, some aren’t.

I go to these things when I can. I love watching the cavalry thundering over a hedge into a battlefield, watching cornstarch float out of a roaring cannon and watching rag-tag soldiers run into the field, guns blazing then ‘pretend-die.’ Fun’s to be had!

There are so many dating websites, yo!

Well, Fluther has some History ‘buffs’, right here.

Are there any museums in his area? As well as their exhibits, most museums host events.

For example, near me, I would send a WWI buff to The First Division Museum at Cantigny and the Pritzker Military Library

If he’s in the eastern US, all the Revolutionary War battlefields would certainly be of interest.

The National WWI Museum is in Kansas City, MO.

He could try looking for people in colleges/universities in the area. There are lots of people in my history classes, at least some of them must be taking these classes because they find history interesting.

NOT SPAM: I got zapped for posting a link so this time I will just write it out because it answers the original poster’s question of :Are there online communities?”. Go to the City-Data history forum and find many people/historians who discuss history, historical inaccuracies, provide “what if“s, etc. For example, a typical thread might be, “What if the US didn’t drop atomic bombs on Japan?”
There is also Historum, a forum dedicated to history. Also try thehistoryforum and allempires.

Here’s a pretty good list of history tumblr blogs. I can’t really vouch for any of the American history or 20th century ones (I’m more of a medieval/early modern Europe fan). This is a list of possible history forums, though most are geared more towards students and professors (but most will happily welcome a history buff so long as they’re a serious buff who isn’t going to totally derail the convo with insane and unsupported theories).