After socialist candidate Salvador Allende won the election, he promised to deal with the issue head-on. In fact, at the beginning of 1971, he sent Congress a project for a constitutional amendment that would allow him to nationalize outright all mines, and to transfer all present and future copper fields to the state. Congress passed this amendment on July 11, 1971, by a unanimous vote, and based on it, on July 16, 1971 law 17.450 was promulgated, and became effective immediately. The event was celebrated as the Day of National Dignity ().