In the 1960s MSU expanded its reputation as a world-grant university, including responding to the invitation of Nigerian President Nnamdi Azikiwe to partner with Nigerians to build the first land-grant model university in Africa, the University of Nigeria at Nsukka. The many years of faculty experience in Nigeria created the foundation for a major MSU African Studies Center. By the 1990s MSU had the largest faculty in the nation of Africa specialists (170) and was producing more Ph.D.s on Africa, offering more study abroad in Africa (26), and teaching more African languages (30) than any other university. The faculty is deeply engaged in many African development problems in food security, health (especially tropical diseases such as malaria, river blindness, and filariasis), education, and gender equity. In 1978, MSU divested the stocks of companies doing business in apartheid-governed South Africa from its endowment portfolio.