WASHINGTON — There are many reasons thousands of teachers traveled across the country to protest in front of the White House on Saturday — including to oppose charter schools, to fight for equal funding for poor schools, and to have more say in public education policies.

But at a noisy rally starting at noon under soaring temperatures, their message boiled down to one point, which was summed up by the sound check before the first speaker took the stage:

Tap. Tap. “No testing, no testing, 1-2-3.”

The assembled teachers, education advocates and parents vented a frustration they said has been building since the passage of the No Child Left Behind law in 2002, which made standardized testing the centerpiece of a school reform agenda championed by George W. Bush.

With the election of Barack Obama in 2008, many thought their longstanding complaints, about how the policy has imposed unfair penalties on the poorest schools and how it has narrowed curriculum to make time for test preparation, would finally be heard.

But three years later, the law is still intact, more schools are being labeled as failing, and standardized tests are starting to be used to make teacher tenure and termination decisions.

“We had reason to believe from his campaign promises that Obama was going to reverse the damage that this law has caused,” said Jonathon Kozol, a public education activist and author. “He has betrayed us. … That’s why we are here today.”

And so about 5,000 people, according to the organizers’ estimates, stood on the Ellipse between the White House and the Washington Monument and waved posters that read “Boycott NCLB” and “Teach Me, Don’t Just Test Me.”

A row of white tents on the edge of the crowd offered shade next to an art display of a graveyard meant to represent “the very real destruction that NCLB has brought to the important experiences and processes of learning.” Most teachers baked on the lawn, waving fans emblazoned with the Washington Teachers’ Union logo.

The “Save Our Schools March” was part of a four-day event including a two-day conference at American University with dozens of workshops, such as “Winning the Testing War” and “Dismantling the School-to-Prison Pipeline.” There was also a half-day strategy session and a film festival, headlined by the documentary “The Inconvenient Truth About Waiting for Superman,” a response to t he 2010 film “Waiting for Superman,” which featured then-D.C. Schools Chancellor Michelle Rhee and which promoted charter schools.

The event, which was endorsed by the two major teachers unions, took about a year and $150,000 to organize. At least a dozen other cities hosted sister rallies or events. The demonstration’s leaders are a core group of teachers, parent activists and education bloggers who maintain that federal policies are too influenced by business leaders and too little by educators who know how policies play out in classrooms.

The White House invited some of the organizers to speak with education policy advisers on Friday, but the organizers turned down the offer, saying they would be willing to meet after Saturday’s march. “July 30 is your opportunity to listen to us,” they said in a news statement.

Bonnie Van Roekel, a 61-year-old music teacher from Commerce City, Colo., said she came to the march because “testing has become a ‘Saturday Night Live’ skit” in her district. Teachers are expected to follow scripts for each lesson, a new strategy intended to boost scores, she said. Like many in the crowd, she wore red (“for public ed”).

The speakers included a long list of longtime education advocates and a few Hollywood celebrities whose mothers are teachers or public education advocates.

“The Daily Show’s” Jon Stewart sent his support by jumbo-size screen rather than driving to the march because, he said, “the dog ate his car.”

Actor Matt Damon elicited cheers when he commiserated with the crowd. “This has been a horrible decade for teachers,” he said. “The next time you feel down or exhausted … please know there are millions of people behind you.”

With that send-off, they marched off the lawn, up 17th Street and around the White House, many chanting, “Education under attack! What do we do? Stand up, fight back.”