WASHINGTON — The Nelson Mandela eulogized to the world by President Barack Obama as “a giant of history” and the “last great liberator of the 20th century” seemed a different person from the one the United States held at arm’s length, to put it diplomatically, for much of his life and career.

Even as presidents from John F. Kennedy to Bill Clinton denounced apartheid as a racist, untenable system, successive American administrations from the 1960s had friendly ties with South African governments and viewed Mandela with suspicion, if not outright hostility, through the prism of the Cold War.

And Mandela remained on a U.S. terrorism watchlist from the 1970s until the late 2000s. That period covers the living presidents of that period — Jimmy Carter, Clinton and George W. Bush — all of whom joined Obama at Mandela’s memorial service in Johannesburg’s Soweto township on Tuesday, as well as Richard Nixon, Gerald Ford, Ronald Reagan and George H.W. Bush.

Even after his 1990 release from prison, his election as South Africa’s first black president and the dismantling of apartheid, the U.S. relationship with Mandela was an uneasy one, notably because of his harsh criticism of Israel, the Iraq war and the U.S. embargo on Cuba. Still, if the U.S. presidents present at Tuesday’s ceremony harbored anything other than good will toward Mandela, it was not apparent and has been absent since his death last week at the age of 95.

Comparing him to Mohandas Gandhi, Martin Luther King Jr., Abraham Lincoln and America’s founding fathers, Obama lauded Mandela for his leadership of a resistance movement, giving voice to the oppressed, holding a splintering nation together.