AMNA NAWAZ: This week marked President Trump's deadline for federal agencies to launch mass firings.

So far, tens of thousands of staff have been forced out.

Courts have reversed some of Trump's moves and upheld others.

This has been a source of pride for the president and a nightmare for many workers.

But, as Lisa Desjardins reports, it's part of a much older debate over the federal civil service.

LISA DESJARDINS: The U.S. government is the largest employer in the country, with three million civilian workers.

They do everything from delivering your mail to keeping our food supply safe to producing legions of studies.

To some, that's an American strength, to others, including President Trump, a bloated system to dismantle.

DONALD TRUMP, President of the United States: We are draining the swamp.

It's very simple.

And the days of rule by unelected bureaucrats are over.

LISA DESJARDINS: President Trump's actions are unique in some ways, firing tens of thousands of federal workers in the first six weeks.

But this debate over the role and size of federal government is nearly as old as this country.

And it is core to how U.S. democracy operates.

BEVERLY GAGE, Yale University: There's been an ongoing contest about what the proper size of the federal government is, what the federal work force should look like, how big it should be, and, in particular, what it should be doing.

LISA DESJARDINS: Going back to President Andrew Jackson in 1829, who quickly cut 20 percent of the federal work force and hired party loyalists.

SCOTT GREENBERGER, Historian: Being hired as a federal worker had everything to do with your political orientation and your loyalty to the party and not much to do with your qualifications or your expertise or your ability to do the job.

LISA DESJARDINS: The so-called spoils system got its name during Jackson's administration.

Political parties controlled government jobs and workers had to pay the party to keep those jobs.

Many believed the system was bent toward corruption.

SCOTT GREENBERGER: Many people felt like there was no way that American democracy could flourish and there was no way that this fast-growing country could flourish without a professional civil service.

We really need people in the federal government who are not just political hacks.

LISA DESJARDINS: And then dramatic events in the 1880s.

A reformer, James Garfield, won the presidency, but he was soon shot by an assassin who opposed reform and supported Vice President Chester Arthur, who was part of the spoils system.

But, as president, Arthur broke with the political machine.

SCOTT GREENBERGER: He surprised everybody, Arthur did, by proclaiming that he had had this change of heart.

He was now in favor of reform.

LISA DESJARDINS: In 1883, Arthur signed a key law, the Pendleton Act, setting up exams for federal workers and limiting much of the role of political parties in hirings and firings.

A meritocracy was born.

FRANKLIN DELANO ROOSEVELT, Former President of the United States: In the working out of a great national program... LISA DESJARDINS: Fifty years later, another significant change, this time to the size of the federal work force.

DAVID LEWIS, Vanderbilt University: When Roosevelt takes office, the national government's probably about 500,000 employees.

By the time he leaves office, it's well over three million.

LISA DESJARDINS: In 1933, Franklin Roosevelt introduced his New Deal to provide jobs and help for the millions of Americans who were unemployed.

DAVID LEWIS: In response to the Great Depression, he dramatically expands the role of the national government.

These government employees are doing lots of new things.

So the federal government's taking new responsibilities in regulating markets and providing social welfare, so we get Social Security and these kinds of things.

And it created a conservative backlash.

LISA DESJARDINS: FDR fundamentally changed what government could do and how it could do it.

MAN: There's the president waving goodbye.

LISA DESJARDINS: In the 1970s, the fallout from the Nixon Watergate scandal sparked another shift, when, in 1978, Jimmy Carter led an attempt to bring more accountability.

JIMMY CARTER, Former President of the United States: This reorganization plan will restore the merit principle to a system which has grown into a bureaucratic maze.

LISA DESJARDINS: Carter's Civil Service Reform Act created the Office of Personnel Management and recognized the right of most federal workers to unionize.

Then, in 1981, Ronald Reagan brought a seismic political shift.

RONALD REAGAN, Former President of the United States: Government is not the solution to our problem.

Government is the problem.

BEVERLY GAGE: The federal work force in particular, he really articulated as being unaccountable, as being inefficient, as being a sort of metastasizing force on the American political body.

LISA DESJARDINS: Reagan fired 11,000 air traffic controllers who went on strike demanding better hours and wages.

But, ultimately, by the end of his term, Reagan would add to the federal work force, in net.

It really wasn't until Bill Clinton took office in 1993 that we saw a modern-day large-scale downsizing of the federal work force.

AL GORE, Former Vice President of the United States: Those forklifts hold copies of budget rules, procurement rules, and the personnel code.

And the regulations stacked up there no longer help government work.

They hurt it.

They hurt it badly.

LISA DESJARDINS: He put Vice President Al Gore in charge of a National Partnership for Reinventing Government, an attempt to make government more efficient.

The Clinton-Gore effort took place over seven years, ultimately slimming a federal work force of about two million down by more than 400,000 people.

ERIC YELLIN, University of Richmond: That's the beginning of not only removing federal agencies and federal employees out of Washington, D.C., right, there's significant exodus of agencies out of the district, but also services to private contracts.

LISA DESJARDINS: Over the past two decades, the share of Americans employed by the federal government has remained nearly flat.

DONALD TRUMP: I got elected on making government better, more efficient, and smaller.

LISA DESJARDINS: And though historians hear some echoes of the Clinton-Gore approach today: DAVID LEWIS: The difference between their approach and the current administration's approach is that they always talked about government workers being good people trapped in a bad system.

And so their emphasis was always on process, not on people.

The magnitude of this administratively is unparalleled.

So, normally we would do this through the budget process with congressional cooperation.

LISA DESJARDINS: Trump and Elon Musk say they are focused on fraud, waste, and abuse and want the U.S. government to shrink.

But their haphazard methods have created confusion and for some agencies dysfunction.

Americans are divided in this area, with a majority saying government is doing too much and a majority also feeling that federal workers are essential.

There is no way yet to gauge the lasting effects of these changes, but they could be wide.

DAVID LEWIS: People not getting their Social Security checks, patents taking longer to approve.

Mistakes are going to increase.

I think the customer service of government is going to decrease as well.

BEVERLY GAGE: We're heading into, I think, a pretty interesting and a pretty daunting experiment in what it's going to be like when some of those things that we have taken for granted are really gone.

LISA DESJARDINS: The Trump White House argues the trade-off, a more efficient government, is worth it.

Others say it destroys what took 200 years to build.

We know this.

In those 200 years of debate over federal workers, no one has seen this until now.

For the "PBS News Hour," I'm Lisa Desjardins.