Every place in the U.S. has its own local government, with their own set of laws and regulations. Some are going to be more or less agreeable than others about allowing a festival in their area. In some places, there are zoning rules about gatherings larger than some minimum number, and requirements for things like an adequate number of toilets. Others might demand that you pay an "impact fee" or hire a bunch of off-duty sheriff's duputies for on-site "security."

And if there have been other events in the same area, the local officials may actually know more about planning and logistics than you do -- if that's true, you should take advantage.

That said, if you're planning an event that will attract more than, oh, a hundred people, it's in your interest to talk to the local government early and often, and work with them on advance planning as much as possible. Just because the event is on your own farm or some other private land, you're still going to have an impact on your neighbors -- you want to make sure that the locals know what to expect regarding traffic, health and public safety at an absolute minimum. If you're planning amplified music, you want to make sure about the noise impact on the neighbors. Can the power grid handle the added load from your sound and lighting? Does the neighbor have animals in a pasture across the fence from your land? And if the entire audience isn't camping on the grounds, where will they sleep -- in a local park, or will they park campers on the side of the road, or fill up all three local motels?

And what kind of audience do you expect? The crowd for a fiddle festival is entirely different from the one that comes to hear punk rock. If you can show that your event will have a positive economic impact -- people spending money in restaurants and motels, opportunities for local civic groups to set up food booths on site or offer supper in the church basement, secondary events like a big local rummage sale and so forth, you might get the local folks on your side. Especially if it's a low-key event that draws families and polite folkies rather than rude heavy metal fans (yeah, those are stereotypes, but they're what your opposition will be playing with).

If something goes seriously wrong, you want the local cops and other emergency responders to know who you are and that they can work with you. The last thing you, as organizer, want is an adversarial relationship with the locals.

So the simple answer is that there is no simple answer. It depends on the local government. But regardless of the regulations, you need to do some serious coordination with local authorities.