Not since the civil rights movement of the 1960s, the assassination of Martin Luther King, Jr., and the violence in the wake of his killing, documented in powerful images by dedicated photojournalists like Flip Schulke and Charles Moore, has the world seen a series of photographs come out of America's Southern heartland as powerful as the ones that filled the front pages in the days and weeks following Hurricane Katrina.

As in those civil rights images, many -- if not most -- of the faces of people who suffered so greatly in Katrina's immediate aftermath were the faces of people of color, those living their pre-hurricane lives on society's margins: people who were too poor, too young or too old, who were unempowered and "without," people who didn't have a safety net and who relied, perhaps foolishly, on their government and its agencies to keep them afloat.

The world's opinion of America in the 1960s was greatly eroded by the shocking images of police and firemen brutalizing fellow Americans, including women and the elderly, with high-pressure fire hoses and setting loose upon them fierce police attack dogs, all because these citizens were marching in peaceful defiance of segregation laws and publicly calling for access to their rights as provided by our nation's Constitution. The world saw pictures back then from an America that hypocritically called out from Washington and the United Nations for global equal rights and human rights, and demanded democracy from foreign governments in foreign lands, while at home in the heartland it actively denied these same rights to its own citizens because of the color of their skin.

The photographic evidence played a pivotal role, one that can't be denied. The pictures from the civil rights movement shamed those in America who believed that their country was founded on principals of true equality, and they shamed our country on the global stage. But these very images and the message they sent to the world about our own government, public policy, and what was then called "the establishment" greatly helped to force social change. Many Americans benefited from the results: the Civil Rights Act of 1964 and the Voting Right Act of 1965 passed and afterwards, for the first time in the United States, African-Americans were elected to public office in the South.

Photojournalists who documented the tragedy and violence and death that came along with the civil rights movement, and their pictures of one of the more shameful chapters of American history, gradually mobilized and amplified a crisis of conscience in a public that had not been moved by protest marches, lobbying, fund-raising dinners, and speeches shouted from courthouse steps.

And now some four decades later, photojournalists in the Deep South are doing it again. Another powerful set of photographs, these from the aftermath of Hurricane Katrina, from the lenses of the photojournalists at newspapers such as The Times-Picayune and The Advocate in Louisiana, the Sun-Herald and The Clarion-Ledger in Mississippi, the Birmingham News, the Mobile Register, and the Anniston Star in Alabama, the Dallas Morning News, The Associated Press, Reuters, AFP, and Getty Images, paint a broad canvas stretching the length of the Gulf Coast, compelling us to confront another tragedy, one that's also sadly about politics and race in America. Once again the world saw on front pages pictures that could lead to a conclusion that not much has changed for blacks in the American South since Moore and Schulke forced us to look deeply at ourselves some 40 years ago.

In fact, in some respects things may be worse: there are now more people of color living in poverty than ever before; family units that at least did something to help support the very old and the very young back then are today broken; social, government, and educational programs whose goal it was to leave no child behind have been cut deeply and the money has instead been spent on war and fighting terrorism; public funds that were intended to be used for reinforcing, repairing, and upgrading critical levees to keep the City of New Orleans above water were spent on other priorities. Scientific warnings from accredited studies, and in-depth reporting by The Times-Picayune, both clearly showing the danger faced by the city and her citizens in the wake of a natural disaster, were ignored by the local, state, and federal governments that exist solely for the protection of their citizens – all citizens.

The photographs documenting the result of that failure are undeniable. In them, again we see that the people who suffered the most from the storm's aftermath and their government's failure to act are people of color.

One is left to wonder what pivotal role the photographs of Katrina's aftermath will play in changing the America of tomorrow. Much of the world's opinion of America was already low before the hurricane, and pictures of entire neighborhoods of families left to cling to the roofs of their houses day after day, pictures of incapacitated people and women and children effectively abandoned in a ruined city filled with filthy floodwater, fire, and anarchy, did nothing to bolster the world's opinion of the United States. In Katrina's aftermath, no amount of speeches and spin will change the perception the world now has of how America responded to a tragedy among her own people.

What's at the core of this story is not a killer hurricane and a week of Biblical flooding; the storm merely tore back the covers to reveal the ugly story of what's really happening in America: an entire portion of our society has been marginalized to live in dire poverty, to live without the resources necessary to help themselves survive a disaster, to try to survive in an economy and political climate where the majority, or the powerful, seem to be willing, if only through the consent of silence and inaction, to allow a certain degree of mortality for people of certain demographics in certain locations to be an acceptable fact, as long as it doesn't wash over into the mainstream of American life.

But the pictures in the aftermath of Hurricane Katrina flooded that reality onto the world's front pages and now everyone sees it, the whole world sees it, and it can no longer be ignored. The photographs are indisputable, showing the truth about human behavior at its best and at its worst, exhibiting the physical evidence of institutional and policy failure, and writing history's first draft of the nasty results of America's economic, political, and cultural racism.

A geophysical act of nature and the flooding that resulted from it has, on the world's stage, called again into question America's true colors, what our politics and economic and racial barriers have wrought upon our citizens and upon ourselves. But the story doesn't end there; what happened after Katrina is really only the beginning.

Not since the 1930s have this many Americans been displaced from their homes by an act of nature working in cahoots with government policies, back when drought and the Dust Bowl joined forces with poverty and federal interests to uproot and move millions of people from middle America and the South westward, toward California. That displacement of an entire regional culture changed America forever, as was well documented by Roy Stryker and the Resettlement Administration (later known as the Farm Security Administration).

The legal condemnation of racism by the courts and the Civil Rights Act, the resulting new laws and the end of sanctioned segregation, changed America forever as well, and again photojournalists played a key role in documenting the changes.

What role does photojournalism have today in telling the bigger story that now stands naked in the daylight, the story unearthed by the winds and floods of Katrina, the story of poverty and politics and the host climate they both sustain, the story of an America that either by policy, silent consent, or ignorance allows abject poverty and racism to still exist?

Katrina laid bare the bigger story of what's really going on in America today for those living on the margins of society and we've seen it, the world's seen it, through your photographs. The challenge facing photojournalists and their editors now is this: what are you going to do about it? History tell us that your images can play a pivotal role in changing society, in changing government, in changing wars, in changing the perceptions of entire nations, and in changing the lives of millions of Americans for the better. Stryker led Dorothea Lange, Walker Evans, Gordon Parks, Carl Mydans, Marion Post Wolcott, and others to photograph and build an unsurpassed record of life in a radically changing America. Moore and Schulke created a memorable record of America's struggle with racism in the 1960s. In both projects, the photographers' and editors' dedication to the story, and the time it took for the story to completely unfold, were not measured in days or in weeks, but in years upon years.

Photojournalism has been called upon once again to assume its proper role in the examination of tragedy, politics, and race in America. It is a story of magnitude equal to the saga of the Dust Bowl of the 1930s and the civil rights movement of the 1960s, and our call to action has just been delivered to us via a hurricane, handed to us on the world's front pages. This is the story of our era, of our present and of our future. It's time now for photojournalists and their editors to start doing something long-term, and something of significance, about it.

This essay appeared in the October issue of News Photographer magazine.