Here are the paths that the members of the House of Representatives took to Congress. Each line represents a Democratic or Republican representative, and circles are the major educational, career and political milestones on their path to the House. Items are not exhaustive nor in chronological order.

The United States does not grant titles of nobility. There are no lords, barons or dukes here. At least, not officially.

Unofficially, however, Congress is made up of people who have credentials and experiences vastly different from those of most citizens. Unofficially, considering education, career, family background and personal wealth, it seems that America has a ruling class — or at least a limited number of ways to enter the halls of power.

Here, we’ve traced the pre-congressional career of every House member in the 116th Congress, showing the narrow but well-trodden paths through prestigious schools, lucrative jobs and local political offices that led the latest crop of legislators to Capitol Hill.

The new House has a notable number of political novices, and more women and people of color than any Congress in history. But a majority of members, even the new ones, still made it to Washington by way of institutions and professions that are out of reach for most Americans.

More than 70 percent of House members were lawyers in private practice, businesspeople (including employees in insurance, banking, finance and real estate) or medical professionals. That work can inform the types of bills they introduce, according to research by Katie Francis, a faculty member at Western Governors University. Doctors sponsor more health care legislation, for example.

In part because Congress is filled with successful white-collar professionals, the House is much, much richer than the people it represents, and affluent politicians support legislation that benefits their own class at the expense of others. Wealthier legislators are, for instance, more likely to vote to repeal the estate tax.

“The rosy notion that lawmakers from business and professional backgrounds want what is best for everyone is seriously out of line with the realities of legislative decision-making in the United States,” wrote Nicholas Carnes, a Duke professor of public policy, in his book “White-Collar Government.”

About 5 percent of representatives don’t have a bachelor’s degree, compared with about two-thirds of Americans 25 and older. Hover to see members with no bachelor’s degree

The path to the House starts with higher education. About half of members graduated from public universities, often in their home states, but more than 10 percent of representatives have bachelor’s degrees from elite, private colleges.

It makes sense to elect educated leaders, and voters seem to think a college education is a necessary qualification for office. But the link between having a degree and being a more effective politician is tenuous. Research on legislators in the United States and in Brazil shows that lawmakers with more formal education are not more productive, more popular or less likely to be corrupt.

The gap between legislators and their constituents is stark in graduate education, too. Almost 70 percent of representatives attended graduate school, but only around 10 percent of Americans 25 and older can say the same.

More than one in three members have law degrees, compared with around 13 percent in the United Kingdom's Parliament. Law school

Among both Democrats and Republicans, lawyers are staggeringly overrepresented: They constitute less than 1 percent of the voting-age population but more than one-third of the House. Perhaps it is natural for the people writing laws to study them first. But the United States is an exception internationally. Research by Adam Bonica of Stanford and Maya Sen of Harvard found that in Sweden, France and Denmark, lawyers make up less than 10 percent of the legislature.

Not only are lawyers more likely to run for office, they are also more likely to win. This success is largely because of the advantage they have in early fund-raising, drawing from professional networks of other lawyers and affluent professionals.

Once in office, lawyers tend to vote in a way that benefits their profession. They are less likely to support laws that would cap awards for damages or regulate legal fees, according to Mr. Bonica and Ms. Sen’s research.

Almost 40 percent of House members, more than half Republicans, cite business experience. Business owners, executives or professionals

In addition to small business owners and corporate executives, the House is filled with people who worked in finance, insurance and banking.

Members with business backgrounds sometimes argue that their “outside the Beltway” experience will enable them to run government more like a business — to reduce grift and waste and to pass laws more efficiently. Indeed, a majority of Americans think the country would be better governed with more people from business and management, according to a 2014 Gallup poll.

House members with business backgrounds get more contributions from corporations and vote for pro-business legislation more often. Other research has shown that states with more legislators who worked in the insurance industry are likely to pass bills more favorable to it.

Fewer than 5 percent of representatives cite blue-collar or service jobs in their biographies. Blue-collar or service job

They include Tom Marino, Republican of Pennsylvania, who worked in factories before law school and Alexandria Ocasio-Cortez, Democrat of New York, who often refers to her working-class experience as a bartender when explaining her left-leaning economic policy positions.

Mr. Carnes notes that there is no dearth of politically ambitious, qualified working-class candidates. And when working-class candidates run, they do just as well as candidates from other backgrounds. But blue-collar workers are less able to shoulder the practical burdens associated with running a campaign — like taking time off from paid employment — and less likely to be asked to run by local party leaders and officials.

To get people with a more diverse set of experiences into Congress, he argues, we need to focus on recruiting working-class candidates at the local level — often years before a potential congressional run.

Nearly one in five members served or currently serve in the armed forces, including the National Guard. Military experience

This is a substantial decline from the early 1970s, when more than 70 percent of Congress had military experience.

Seventy percent of veterans in the House are Republicans — but several Democratic women elected in 2018 made their military experience a focus of their campaigns, including Chrissy Houlahan, Democrat of Pennsylvania, who served in the Air Force.

Common fields for Republicans include medicine, real estate and farming. For Democrats, they include teaching, nonprofits and unions. Experience in one of the above fields

There are rarer occupations, too. Colin Allred, Democrat of Texas, played for the Tennessee Titans in the N.F.L. before becoming a lawyer. Jody B. Hice, Republican of Georgia, served as a pastor before stepping down to run for office. He also started a conservative talk radio show.

Other professions are underrepresented, with material consequences for lawmaking. Only about 15 United States representatives are scientists or engineers, which could partly explain lackluster action on climate change and ineffectual regulation of technology companies.

Women tend to have followed more varied paths to Capitol Hill: A smaller proportion are lawyers and businesspeople. Female representatives

While men might run for office because of a “longstanding desire to be an elected official,” women are more likely to run because “they encounter something in their engagement with the political system that angers them enough or frustrates them enough,” said Kelly Dittmar, a political scientist at Rutgers University’s Center for American Women and Politics.

When they run, men and women have roughly the same chance of winning. But research by Sarah A. Fulton, a political scientist at Texas A&M University, shows that female candidates tend to be more qualified.

Many female representatives campaigned on their experience in business and the working world. Some, like Ann Wagner, Republican of Missouri, also highlighted more traditional domestic roles. Her website says her “most important jobs,” despite her previous role as ambassador to Luxembourg, “have always been as a wife, mother and now grandmother.”

Only 20 percent of House members did not hold previous political office before entering Congress. No previous political office

Historically, it is somewhat rare for representatives to reach the House without holding previous political office. Nearly 200 representatives have experience in a state legislature; others were mayors, local district attorneys or state agency heads. These experiences aren’t just symbolic. New legislators with political experience introduce and pass more bills, according to Ms. Francis’ research.

But drawing politicians from local governments and state legislatures also gives an edge to people who can afford to take those jobs. In some states, those positions don’t pay enough to live on. New Hampshire’s legislature, for example, pays just $200 per two-year term. As a result, state politicians are often “local economic elites and corporate titans,” said Jake Grumbach, a researcher at Princeton.

The new representatives in the 116th Congress, however, do represent a significant break from the past. More than 40 percent of those elected in November are political novices who have never worked in government. Many were inspired to run in order to stand up to President Trump’s agenda — two-thirds of new members are Democrats — but they may also have been emboldened by Mr. Trump’s lack of political experience.

“That hasn’t translated into lots of working-class candidates in this cycle,” Mr. Carnes said, but “the larger narrative I see on both sides is, ‘You don’t have to be an establishment type to be a good politician.’”