https://www.ilwu.org/local-10-delegation-marks-50th-anniversary-of-the-durban-strikes/

On multiple occasions across three decades, members of ILWU Locals 10 and 34 as well as Local 6 and other ILWU locals supported the global struggle against apartheid. First in 1962, again in 1977, and most importantly, for 10 days in 1984, rank-and-file dockworkers refused to unload South African cargo in the Port of San Francisco. Bill Chester, then an ILWU International Vice President, was active, as was the Southern Africa Liberation Support Committee, a rank-and-file committee established inside Local 10, in 1976. Leo Robinson, Larry Wright, Charlie Jones, Billy Proctor, Leron “Ned” Ingram, Howard Keylor, Jack Heyman, Dave Stewart, and Archie Brown were among those active in those years. These rank-and-file driven work stoppages were unprecedented in the United States, though workers in some other countries also engaged in similar actions in solidarity with the struggle against apartheid. In 1990, Nelson and his then-wife, Winnie Mandela, visited Oakland, the last stop on their first tour of the U.S. At a packed Oakland Coliseum, Mandela devoted the first ten percent of his speech to thanking ILWU Local 10 for standing down in solidarity with Black workers in South Africa.