An additionally and much harsher sanctions bill was passed by the House of Representatives (Congress) in August 1988. This bill mandated "the withdrawal of all U.S. companies from South Africa, the sale by U.S. residents of all investments in South African companies and an end to most trade, except for the import of certain strategic minerals". In the end, the bill didn't become law as wasn't able to pass the Senate. (In the United States legislative system a bill must be passed by both the Senate and the House of Representatives before it can be signed into law by the President.) Even so, the fact that such a harsh bill made any progress at all through the legislature "alerted both the South African government and U.S. business that significant further sanctions were likely to be forthcoming" if the political situation in South Africa remained unchanged.