Bail, guaranteed by the 8th Amendment of the U.S. Constitution insures the Court that a criminal defendant will appear for trial.
While the English common law system allowed bail, it was generally only for those of the very upper class and even then was given at the whelm of the ruling class. When our forefathers created the United States Constitution, their intent was to guarantee certain rights to all citizens of this country. They wanted to guarantee that the inequities foisted upon them by the English Crown would not happen again.