Current procedural law has had a long historical evolution. The early common law allowed an action to be brought only if it closely conformed to a writ. Rigorous enforcement of the rule "no writ, no right," and the small number of available writs acted to deny relief even in meritorious cases and stimulated the growth of equity, which, in its early days, gave redress generously.
By the 19th cent., however, the technical intricacy of equity and law procedure and the tendency to make cases hinge on procedural details rather than on substantive rights made reform imperative. The way was led by the New York code of civil procedure of 1848 (largely the work of David Dudley Field), which abolished the distinction between law and equity (thereby effecting great simplification) and established the cause of action as the procedural cornerstone. A similar reform was accomplished in Great Britain by the Judicature Acts of 1875. Today the procedure of most American jurisdictions is based on codes (like that of New York) rather than on common law and equity, although the influence of these separate categories is still frequently discernible.