The first bill to become a law in spite of a presidential veto was the

A pocket veto is a bill that still becomes law despite the act of a veto on behalf of the president. The reason that the bill becomes a law is that the president does not veto the bill within ten days. Once the ten days have lapsed, the bill will become a law regardless of whether the president vetoes the bill after.

Because broadest terms allows the law flexibility depending on changing society and circumstances.