Here's a lesson in US church history from Tim Keller from his article on Why Plant Churches?
In 1820, there was one Christian church for every 875 US residents. But from 1860-1906, Protestant churches planted one new church for increase of 350 in the population, bringing the ratio by the start of WWI to just 1 church for every 430 persons.
In 1906 over a third of all the congregations in the country were less than 25 years old. As a result, the percentage of the population involved in the life of the church rose steadily. For example, in 1776, 17% of the US population was 'religious adherents', but that rose to 53% by 1916.
After WWI, church planting plummeted. One of the main reasons was the issue of 'turf'. Once the US was covered by towns and settlements and churches and church buildings in each one, there was strong resistance from older churches to any new churches being planted in 'our neighborhood'.
New churches are commonly very effective at reaching new people and growing for its first couple of decades. But the vast majority of congregations reach their peak in size during the first two or three decades of their existence and then remain on a plateau or slowly shrink.
Older churches feared the competition from new churches. Mainline congregations, with their centralized government, were the most effective in blocking new church development in their towns. As a result, mainline churches have shrunk remarkably in the last 20-30 years.
What are the historical lessons?
Church attendance and adherence overall in the United States is in decline and decreasing. This cannot be reversed in any other way than in the way it originally had been so remarkably increasing. We must plant churches at such a rate that the number of churches per 1,000 population begins to grow again, rather than decline, as it has since WWI.