The area north of where I'm sitting was used as a Methodist campground from 1869 into the 1920's. It's also locally known as Tiny Town because of the small size of the cottages and small streets that encircle the camp, one inside of each other.
Religious activity was at its peak in the 1860's and Methodists from all over New York State met here every year for ten days. The campgrounds attracted anywhere from 300 to 10,000 people. They would park their wagons inside the circles and live out of them. Eventually, some of the parishioners built small cottages instead of living out of the wagons. There was also a chapel and a minister's house built, which are local residences today.
These "camp meetings" were held all over the United States. With no permanent villages to contain the influx of new settlers and the lack of parishes, there arose a need for a place where Christians could worship thus the Campgrounds were born. Similar to the revival meetings, these camp meetings were often led by traveling ministers who solved the problem. The crowd literally "camped out" especially if it was a few miles away from their homes. They could either stay for the entire meeting or leave after a few days. Continuous services were held in which parishioners would take part. Hymns and religious song filled the air.
There are camp meetings still held today in the United States mostly held by the Pentecostal and Wesleyan religious groups.
There are some links that I will include here.
This Wikipedia article will explain more on the camp meetings:
Merrick Methodist Church site includes history of Merrick and the campgrounds.
History of Merrick page.
New York Times article on Tiny Town
Here is the Wikimapia site showing the circular streets