Since President George W. Bush has, by some measures, had the most diverse cabinet in U.S. history, I thought it would be interesting to compare President-elect Obama's picks for the cabinet to see how they compare just on this one measure. I'm not talking ideological diversity here. I intend to reflect on that at some point. I'm simply talking about the standard kinds of diversity usually intended when people use the word, and the only ones I've ever heard people discuss with the cabinet are race/ethnicity and sex/gender. I'll go position by position. I'm only including full appointments with Senate confirmation, not acting secretaries. I'm also only counting cabinet secretaries, since the precise list of which other positions are in the cabinet varies with each president.
Madeleine Albright was the first woman to hold the position of Secretary of State, under President Clinton. Colin Powell replaced her and was the first black in the office. His replacement, Condoleeza Rice, was the first black woman. Obama chose not to go with a new first here, appointing Hillary Clinton, another woman.
As far as I can tell, there has never been anyone but a white man to hold the office of Secretary of the Treasury. That will not change under President Obama, at least not at the start of his term. Timothy Geithner certainly has a diversity of experience, but he's another white man. Diversity isn't the only consideration Obama should have factored in, but it's fair to say that he did miss an opportunity here to appoint the first person to this office who isn't a white man. If he appoints another person to this officer later, that might be a strong consideration.
The same goes for Secretary of Defense. The difference here is that Obama is just continuing the current occupant of that position in the interest of smoother transition in time of war.
Bill Clinton appointed Janet Reno as the first woman Attorney General. George W. Bush appointed Alberto Gonzales as the first Hispanic Attorney General. Obama has nominated Eric Holder to be the first black Attorney General. In his case, I have slightly more doubt that he'll be confirmed when compared with most of Obama's picks, because even if you ignore ideology there are excellent reasons not to confirm him given his leading role in Clinton's most unconscionable pardons (not just Marc Rich but a group of domestic terrorists who should never have been considered, never mind approved, for pardon) and his defense of pointing guns at small children by calling it respectful (in the Elian Gonzalez affair). Either is sufficient grounds to wonder if he's qualified to be the nation's chief law enforcement officer. But the Senate will probably roll over for Obama and confirm him anyway.
George W. Bush appointed the first woman Interior Secretary, Gale Norton. I'm not 100% sure of this, but I believe Obama's nomination of Ken Salazar would make him the first Hispanic Interior Secretary.
Mike Espy, Clinton's Secretary of Agriculture, was the first black person in that position. Ann Veneman, under George W. Bush, was the first woman to hold the office. Obama's nominee is a white man.