Less than a month before U.S. B-29s flew over Japan and leveled Hiroshima and Nagasaki with the only two atomic bombs ever used in combat, a bomb was mounted on a tower in the Middle of Nowhere, New Mexico, and set off.

The Trinity Test made history, offering proof that America’s WWII dash to build a war-ending bomb, The Manhattan Project, was not in vain.

But “middle of nowhere” was in the middle of somewhere. Trinity, now in the White Sands Missile Range, was a desert with scattered villages and towns — Tularosa, Carizoso, Bingham, Ruidoso — 30 to 50 miles away, downwind.

And while the scientists involved with the Project weren’t sure about exactly what would happen with the blast, the levels of radiation and its short term and long term impact on the region and any livestock and people nearby, they made damned sure that Trinity was a couple of hundred miles downwind of where they were doing their work in Los Alamos.

“First We Bombed New Mexico” is about the “Downwinders,” the people in this towns which were illuminated by a flash and rattled by a boom that the military told New Mexico newspapers at the time was “an ammo dump” exploding. There were children who played in the “snow” of fallout, who faced rare cancers that erupted far out of proportion to the population in general, ranchers and farmers who got sick and died before their time, people who passed down this cancerous legacy in a place that wasn’t safe to remain in during an atomic blast or live in after the effects of that blast swept downwind.

Mostly Latino and Native American, they weren’t evacuated before, during or after the test. When the government finally started to acknowledge the damage nuclear research and testing had done to the unwitting victims in the U.S. with the Radiation Exposure Compensation Act (RECA), these “downwinders” were left out.

Filmmaker Lois Lipman’s “First We Bombed New Mexico” follows victims, first generation and their descendents, as they meet, protest and try to draw attention to their plight as the RECA act rumbles towards a summer, 2024 cut-off date for recognition and claims.

Victim and activist Tina Cordova and others attempt to awaken the conscience of the country, and Congress, to their plight as “the first victims of an atomic bomb.”

A local doctor describes her efforts and those of earlier physicians to draw attention to the vast spike in infant deaths and the rare cancers that blew up in the months and years after Trinity.

An historian gives us an abridged context, as we hear then-President Harry Truman, and have his thoughts on some of the haste and carelessness that went on (a rainstorm coincided with the test) as Truman wanted to break the news to Stalin and the Soviets about the bomb at the summer, 1945 Potsdam Conference in Germany between the victorious European allies.

One activist describes the government’s refusal to acknowledge its culpability and racism in refusing to consider evacuating the working poor Native American and Latino residents before the blast, or after, as “atomic colonialism.” And the major barrier to getting Congress to expand RECA to acknowledge these victims has been and continues to be Congressional Republicans.

Meanwhile, the surviving “downwinders” testify and scramble to get RECA recognition before they all die out.

Documentaries about The Manhattan Project tend to focus on the achievement, with many parts of the country playing a part in the Race to Build the Bomb. I worked on one for a regional PBS affiliate right out of college.

But as Christopher Nolan’s “Oppenheimer” points out and we’re reminded, in archival intereviews with Dr. Oppenheimer, the brains behind the porject had misgivings, right up to and ongoing in the decades after Trinity, Hiroshima and Nagasaki.

The effects of all that radiation, plutonium’s insidious “half-life” that might impact “7,000 generations” living on contaminated land, weren’t grasped. And when they were, decades of evasion, obfuscation and denial followed the risks that were shrugged off, minimized and buck-passed during the urgency of World War II.

Lipman’s fine film shines a light on this tragic injustice and as it makes the rounds of film festivals and into release, attempts to light a fire under those still resisting efforts for recognition and justice.

Rating: unrated

Cast: Tina Cordova, Laura Greenwood, Paul Pino, Katherine Douglas, Joshua Wheeler, Kate Brown, and (archival footage) J. Robert Oppenheimer.

Credits: Directed by Lois Lipman, scripted by Lois Lipman and Joel Marcus. A 47th State film.

Running time: 1:38