As it stands, much of the historical account of US foreign policy towards South Africa ends in the mid-1980s. Little academic literature looks beyond 1986, and the imposition of US sanctions underwritten by the Comprehensive Anti-Apartheid Act (CAAA). This article offers an analysis of US policy in the wake of the CAAA, covering the 1986–1994 period. It charts the adaption of the Reagan Administration's constructive engagement policy, and then considers how Washington DC engaged South Africa's negotiation process and this country's transition to a new non-racial democratic state. In contrast to US policy prior the CAAA, Washington DC's post-sanctions strategy proved effective. By building a working relationship across South African society, US diplomats were able to play a useful role in apartheid's endgame. The article does caution, however, that the impact of this US assistance can be overstated, as has occurred in diplomatic memoirs. It is argued that this foreign policy netted a significant but minor contribution.