Carl Henry, in the second video on this page, paints a clear picture of the modernism that, he says (and I agree), co-opted the American church at the turn of the last century. He even uses a little appropriate humor:
Modernism’s deepest assumption was that the scientific method of laboratory duplication and verification is the supremely reliable way of knowing. This presupposition struck at the very heart of miraculous supernaturalism, of miraculous revelation, miraculous atonement, miraculous resurrection. It allowed no credibility to any event claim that could not be duplicated. No historical act was to be admitted as credible unless it occurred at least twice, the second time at a command performance by the modern observer.
Evangelical orthodoxy, with its emphasis on the once-for-all virgin birth of Christ, his substitutionary atonement and bodily resurrection, was accordingly declared to be unscientific and prescientific.