Americans today face an existential threat to our democracy and our rights, but not for the first time. In the past, Americans have transformed similar threats into opportunities to realize bold and ambitious new visions for America. We must now do the same.

During the Revolutionary War, as America’s founders fought against the injustices of the English monarchy, delegates from the thirteen colonies came together to declare independence and create a new nation. On July 4, 1776, they signed the Declaration of Independence, which rejected the tyranny of King George and set forth an ambitious and unprecedented vision for America: that all people are created equal and endowed with “unalienable Rights,” including “Life, Liberty and the pursuit of Happiness.”

Nearly a century later, as Americans fought a second battle against the tyranny of slavery, a new and equally ambitious agenda for the nation emerged. During the Civil War, after 50,000 people died at the Battle of Gettysburg, President Abraham Lincoln delivered the now iconic Gettysburg Address on Nov. 19, 1863. In it, he declared, “that these dead shall not have died in vain — that this nation, under God, shall have a new birth of freedom — and that government of the people, by the people, for the people, shall not perish from the earth.” In the ensuing years, the nation enshrined that vision into law by passing three constitutional amendments that abolished slavery, granted citizenship and equality to all people, and enshrined voting rights.

In the 1930s, amidst devastation wrought by the Great Depression, President Franklin Delano Roosevelt offered a fresh vision for America: the New Deal. His administration launched foundational social welfare programs that we still rely on today, including Social Security, unemployment insurance, and labor protections that fundamentally redefined the role of government. “The test of our progress,” said Roosevelt, “is not whether we add more to the abundance of those who have much; it is whether we provide enough for those who have too little.” He called on the country to rise to the challenge before them: “This generation of Americans has a rendezvous with destiny.”

The 1960s was another turning point in our nation’s history. As Black Americans marched for civil rights and equal participation in society, white Americans attacked them with billy clubs, snarling dogs and firehoses. Once again, a great leader emerged to meet the moment. On Aug. 28, 1963, the Reverend Dr. Martin Luther King Jr. articulated his vision: “I have a dream that one day every valley shall be exalted, every hill and mountain shall be made low, the rough places will be made plain ... With this faith, we will be able to hew out of the mountain of despair a stone of hope.” In the years following, President Lyndon B. Johnson signed landmark civil rights legislation — outlawing race discrimination, protecting voting rights and opening the door to increased immigration, helping to build our multi-racial, multi-ethnic democracy that has fueled American progress and prosperity over the last 60 years.

These four periods — the 1770s, 1860s, 1930s and 1960s — were critical inflection points in our nation’s history when we faced existential threats that were moments of rupture that created opportunities to reimagine what America could be —to pursue ambitious and inspiring new directions.

We are once again at a turning point in America. As our democracy crumbles around us, we have the opportunity to envision an entirely new future — one that is more equal, more just, more caring and that truly lives up to our founding ideals of “life, liberty and pursuit of happiness” for all. Will we rise to meet this moment as our forbearers have repeatedly done? Rather than attempting to restore what we had before Donald Trump, we must conjure a “new birth of freedom” that is truly “of the people, by the people, for the people.”

I invite you to dream about the society you would like to see and we deserve. I dream of a society with a fair economy, where everyone has access to living wage jobs, paid family and medical leave and a guaranteed minimum income. Housing is plentiful and affordable. Everyone has accessible, high-quality health care, including contraception and abortion. This is a society with free, high-quality child care, fully resourced public schools, and tuition-free college and graduate education. A society with clean air, water and land. A society that invests abundantly in art and culture, and disinvests from weapons and war.

What is your dream?

I urge you to focus on what we are fighting for, not just what we are fighting against. Like those before us, we can transform the current crisis into an opportunity. We can carry America closer to its founding principles by advancing a bold, unapologetic vision for a future rooted deeply in the long American tradition of calling for liberty, equality and justice.

We, today, face our generation’s “rendezvous with destiny.” Let us meet this destiny with clarity, courage and a vision worthy of the future we deserve.

Carrie N. Baker is a professor in the Program for the Study of Women and Gender at Smith College and a regular contributor to Ms. Magazine.