Wasn't Martin Luther King the first black president?

I went to have my hair cut this morning, here in London in the UK. Two of the trainees were talking. One was saying that she had been inspired by Obama being elected as U.S. president, and had decided that she wanted to go into politics herself. The other said something like "they keep saying he is the first black president, but wasn't Martin Luther King the first black president"? So much for skoolin', I guess.

Update: here is a link to the Wikipedia article on Martin Luther King Jr.