America’s mainline churches, once a vibrant part of American religion, have been in a state of decline for decades. At least that’s the story that’s often told. But it’s only half-true. Yes, the Protestant establishment churches have seen a drop in membership. But the churches—as institutions—remain strong with more clergy today than ever before.
During the first half of the 20th Century, the mainline was on the rise. In raw numbers, these churches nearly doubled in size from from the 1930s to 1960s. After leveling off during the 1960s, membership in mainline churches began to decline.
– See more at: http://tobingrant.religionnews.com/2015/06/02/mainline-decline-depends-on-what-youre-counting/#sthash.lrcH1rur.dpuf