The "Marxist Workers Tendency (MWT) of the ANC", was founded in 1979 by Mark Heywood, Paula Ensor, Dave Hemson and Martin Legassick. The MWT was a result of a conflict with the South African Congress of Trade Unions (SACTU) and the then exiled African National Congress (ANC), trying to persuade them to commit to policies towards a socialist revolution in South Africa.
During that time Mark Heywood was instrumental in setting up the Philemon Mauku Defence Campaign and the Leeukop Political Prisoners Support Committee.
The documents submitted in 2016 relate mainly to his post-1994 activism as part of organisations such as the Centre for Applied Legal Studies (CALS); the AIDS Law Project (ALP), which evolved from CALS and which was later incorporated into 'Section 27', where Mark Heywood served as Executive Director at the time of the additional submissions; and the Treatment Action Campaign (TAC). The documents also include some personal papers.

The project was designed to complement the existing labour collection housed at Historical Papers and to ensure that South African labour/human rights documentation which is under threat is preserved and made easily accessible. The Project recognised the dynamic potential of oral history and testimony in providing a meaningful context through which the labour movement in South Africa can be documented in its full complexity, and communicated in ways that illuminate the specific historical, political and cultural contexts in which it occurs.