The correct answer is: Before, witnesses did not have to testify in court.
The Confrontation Clause, found in the Sixth Amendment of the U.S. Constitution, guarantees a defendant the right to confront and cross-examine witnesses testifying against them in a criminal trial. Before this provision was fully recognized, defendants could face trials where witnesses did not have to appear in court, which could lead to unjust convictions based on hearsay or unchallengeable testimony.