In the year of 1846, the Democrat David Wilmot, set a precedent in the United States House of Representatives, proposing to the Congress an essay for a law known as -the Wilmot Proviso-. The amendment was intended to forbid slavery within the lands won as a result of the Mexican- American War from 1846.although the proposal in the United States Congress to ban slavery in territory gained from Mexico in 1847 was tried to carry on. Historians point to the fact that the southern states were reinforcing slavery practices so it was hard to have been carried on.
The answer is :The Wilmot Proviso
