President-elect Joe Biden on Wednesday nominated former South Bend, Ind., mayor Pete Buttigieg to serve as the head of the Transportation Department in his administration.

Normally, such an announcement would be at best rote or, more likely, boring: Oh, a former mayor from Indiana is going to run Transportation? Wake me up when we get to attorney general. But Buttigieg is not just a former mayor. He is also an openly gay former mayor — putting him on the brink of being the first openly gay person confirmed to hold a position in a presidential Cabinet.

He won’t be the only person to break new ground in American politics. Given the tumult that has followed last month’s election, Vice President-elect Kamala D. Harris’s own bit of history-making has gotten a bit buried. But she’ll not only be the first woman to hold the position, she’ll also be the first Black person and woman of Asian descent to do so.

For most of American history, of course, most positions of leadership, from the three branches of government to the executive mansions in each state, were held by straight White men. Most of those positions still are, of course. But over the past century, more and more such positions have been held by people of color, women and members of the LGBTQ community.

Here’s when each branch of government and state governorships were first held by people other than White men.

Presidency

So far, only one non-White man has held the nation’s top job: Barack Obama, who entered office in 2009. There may have been a gay president, however, according to historians. As Ezekiel Emanuel wrote for The Washington Post last year — in the context of a potential Buttigieg presidential nomination — historians say that James Buchanan may have been gay, though, given the era, not overtly so.

Vice presidency

While Harris will be the first vice president to fall within a number of these categories, there may also have been a gay vice president. Historians say that Franklin Pierce’s vice president, William R. King, may also have been gay — in part because of his lengthy personal relationship with Buchanan.

The first vice president of Native American ancestry was Charles Curtis, a politician from Kansas who belonged to the Kaw Nation. He served as Herbert Hoover’s vice president.

Cabinet

If Buttigieg becomes the head of the Transportation Department, he will be the first openly gay person to be confirmed by the Senate. But President Trump’s appointment of Ric Grenell to serve as acting director of national intelligence made Grenell the first openly gay person to serve at the Cabinet level.

Most of the other non-White officials and women who served in presidential Cabinets were confirmed to those positions within the past 60 years. The exception is Frances Perkins, who served as labor secretary under Franklin Roosevelt.

House and Senate

Both chambers of Congress remain heavily White and male, but the first non-White members of each body were elected in the 19th century. Women weren’t elected to either chamber until about a century ago, with the first female senator, Rebecca Felton of Georgia, earning that position through gubernatorial appointment.

It’s only been within the past 60 years that a non-White woman was elected to the House (Patsy Mink of Hawaii) and only within the past 40 years that a non-White woman (Carol Moseley Braun of Illinois) was elected to the Senate.

As was likely the case with the presidency, there were gay politicians in the House and Senate who were not open about their sexuality. Buchanan, for example, served in both chambers before being elected president. Other politicians announced their sexuality or were revealed to be LGBTQ after leaving office. Harris Wofford of Pennsylvania married his partner in 2016 after serving in the Senate. Stewart McKinney of Connecticut, who’d served in the House, was revealed to be gay only after he died of AIDS in 1987.

The first openly gay person elected to the House was Gerry Studds of Massachusetts, who was reelected multiple times after he was censured for his relationship with a congressional page. Sen. Tammy Baldwin (D-Wis.) was elected as the first openly gay senator in 2012.

Supreme Court

As with the presidency, there have been relatively few Supreme Court justices and, therefore, relatively few who weren’t White men.

The first Black justice was Thurgood Marshall, appointed by Lyndon Johnson. Ronald Reagan appointed the first woman, Sandra Day O’Connor. Sonia Sotomayor became the first non-White woman and first Hispanic member of the bench when confirmed in 2009.

Governors

It wasn’t until the 20th century that the first non-White governors were elected to office. (Two non-White governors served before that point, having assumed the position because of the sitting executives leaving office.) The first Black governor wasn’t elected until Douglas Wilder won in Virginia in 1989.

The first openly gay governor was New Jersey’s Jim McGreevey — though he was openly gay as governor for only a few weeks after a scandal involving a sexual relationship prompted him to announce his resignation in 2004. The first LGBTQ governor elected to office was Oregon’s Kate Brown, who won in 2016.

What a review of the diversity of American leadership positions makes clear is how much uncertainty surrounds the subject. Race, ethnicity and sexuality are less concrete than we generally consider, leading to various judgment calls on who ought to be identified as having been the first individuals in any particular category to hold a position. If you disagree with our assessments, let us know.

The chart above doesn’t capture a more important point — that these positions being held by people who aren’t men or aren’t White continue to be the exceptions.

A good example of that runs as an undercurrent through this article. We mentioned Moseley Braun, the first Black woman to serve in the Senate, and Harris, who will leave the Senate to serve as vice president.

There have been no other Black women who have served as senators.