Each year on this day, Americans celebrate our founding principles and the birth of our nation, but in these chaotic and polarized days, it is also important to remember that the United States was born from a crisis of unity and has experienced two more at roughly 70-year intervals — the Civil War and the Great Depression.

Both nearly tore us apart, yet each sparked a civic rebirth. After each great rupture, the government was restructured; each took the nation closer to its founding ideals; each brought greater liberty, justice and opportunity to expanding groups of Americans; each changed forever and for the better the relationship between government and the people.

We’re now in the midst of a fourth crisis, from which will emerge the next agreement about how and for whom our government operates. Will it produce a constitution that once again advances our founding principles and expands opportunities, or will this be the first American crisis that institutionalizes a stripping of rights, freedom and wealth?

In past crises, the nation found the will and leadership to correct its course. Will we be so blessed again?

More fundamentally, will the structure of our present political process allow us to select the right leader, should she or he emerge? Or will the power brokers of our parties work to eliminate the candidacy of a potential Washington, Lincoln or Roosevelt?

A nation’s constitution is not just contained in a document but includes as well the practices and agreements that determine how government operates and what it’s permitted to do. In that sense we’ve been governed not by one constitution but by three.

The first grew out of armed revolt against the British Crown, but it also sprang from revolt by the emerging manufacturing and merchant classes against colonial status. Americans wanted to compete alongside the British economy and not be forced into the role of mere consumers.

From that revolution came the original U.S. Constitution — slave-enabling and voter-restricting, yes, but largely democratic — and from its government came the policies of Alexander Hamilton, which gave American manufacturing its first strong boost.

The second constitutional agreement grew from a mainly nonviolent revolt in the North against slavery, an institution that sustained the Southern economy. This threat to slavery produced a bloody Southern revolt against the national government. The social aspects of that conflict still rip our society, but the constitution that emerged — that of the 13th, 14th and 15th amendments — was radically different: It abolished slavery, established equal protection as a fundamental right and greatly expanded the vote.

Each of the first two crises broke into violence — the Revolutionary War, the Civil War — before producing constitutional change. The third, the Great Depression, also produced a revolution of our politics and governance, but one in which violence was averted by Franklin D. Roosevelt’s election and bow to the need for a restructured government. This led to vast reforms, citizen-protecting regulation and the economic-opportunity programs known as the New Deal.

Each crisis resulted in a constitution that brought us closer to our principles: the original Constitution bound the separate states into one country; through amendment an anti-slavery document replaced the pro-slavery original; and through reinterpretation of the Commerce Clause and other changes, the New Deal constitution overturned the laissez-faire government from which it evolved.

Through each, the nation righted itself. Crucially, success also depended on the emergence of the right political leader — and by the people’s ability to elect him.

Our nation is once more in the grip of division and change. When we emerge, the United States will be different. Our government and society will once more be restructured and new rules will be decided.

What will the next American constitution look like, given the trajectory of the Trump presidency and the swirl of conflict around it? Like Turkey’s and Hungary’s, with dictatorial government wrapped in old constitutional forms? A naked kleptocracy, where forms and norms are simply ignored?

With the resignation of Justice Anthony Kennedy and Sen. Mitch McConnell’s rush to confirm a Trump appointee — an opportunity he openly denied the previous president — we see yet another attempt to turn the constitution on its head.

Impeachment is our formal protection against presidential misadventure, not just a way to address proven violations of the criminal code. Could a lack of impeachment enshrine in our practices continued debasement of our democratic norms and principles? Is impeachment alone sufficient to correct our course?

We are already changed by what led us here, and the political, racial and economic dysfunction that so many rejected with their votes in the 2016 election cycle shows no sign of ending without another restructuring of government. This crisis of unity has brought us to transition, no matter what happens to Donald J. Trump.

The past three times our government was forced to change, we chose leaders up to the task of correcting our national course to the benefit of increasing numbers of Americans.

Will we get that lucky again?

Thomas Neuburger is an essayist, poet and story writer. He has published political analysis under the pen name Gaius Publius since 2010.