Until 1965, the Confrontation Clause of the Sixth Amendment to the United States Constitution hardly mattered. It was not applicable against the states, and therefore had no role whatsoever in the vast majority of prosecutions. Moreover, if a federal court was inclined to exclude evidence of an out-of-court statement, it made little practical difference whether the court termed the statement hearsay or held that the evidence did not comply with the Confrontation Clause.
Friedman, Richard D. "Crawford, Davis, and Way Beyond." J. L. & Pol'y 15, no. 2 (2007): 553-633.