RICHMOND, Ky. (AP) — After decades of living in the shadow of chemical weapons, a Kentucky community on Wednesday celebrated the final destruction of the arsenal — culminating what Senate Republican leader Mitch McConnell called a “once seemed unimaginable” achievement marking a new era in U.S. defense policy.

The milestone was reached in July, when workers destroyed the last rockets filled with chemical nerve agent that had been stored at the Blue Grass Army Depot near Richmond. It completed a decadeslong campaign to eliminate a nationwide stockpile that by the end of the Cold War totaled more than 30,000 tons (27,200 metric tonnes).

“Chemical weapons made peace uneasy in our modern world, and the U.S. and our allies must continue to condemn the use of these vile weapons and punish those who deploy them,” McConnell said during the celebration. “Today, however, we stand on the threshold of a new era in American defense — one without these weapons of terror. This achievement is as much a global victory as it is a local triumph.”

The Kentucky Republican joined state and local leaders as well as Defense Department officials to pay tribute to the workers given the painstaking assignment of destroying the weapons, closing a chapter of warfare dating back to World War I.

“Today, our nation and the American people are safer because the hard-working citizens of the commonwealth of Kentucky delivered,” Democratic Gov. Andy Beshear said.

McConnell, the longest-serving Senate party leader, called it “one of the great honors” of his career to be at the forefront of the long-running campaign to destroy the weapons.

“Together, we achieved what once seemed unimaginable,” McConnell said. “And together now, Madison County celebrates the triumphant close of this chapter in American history.”

The weapons’ destruction was a major watershed for Richmond and Pueblo, Colorado, where an Army depot destroyed the last of its chemical agents earlier in the year. It was also seen as a defining moment for arms control efforts worldwide. The U.S. faced a Sept. 30 deadline to eliminate its remaining chemical weapons under the international Chemical Weapons Convention, which took effect in 1997.

McConnell got involved at the urging of citizens who opposed the Army’s plan to burn the weapons. The senator stayed engaged over the decades by steering massive amounts of federal dollars to the disposal effort. In 1996, McConnell introduced and won passage of legislation that led to efforts to identify and demonstrate responsible alternatives to incineration at the Kentucky facility, the senator’s office said.

Officials settled on using a process known as neutralization, which removes the deadly chemical from a projectile and dilutes it in a solution.

“For many Americans, the international ban on chemical weapons may seem distant from their daily lives,” the senator said Wednesday. “But for the people of Kentucky, especially right here in Madison County, this commitment has been deeply personal.”

“Kentucky has been home to over 500 tons of chemical weapons, including mustard, sarin and VX, since way back in the 1940s, and for years, the community coexisted with these munitions,” he added.

Richmond, situated along the edge of the Appalachian foothills, is 27 miles (43 kilometers) southeast of Lexington.

McConnell credited Craig Williams, a Vietnam War veteran and local environmental activist, for his expertise and years of work on the project. He thanked Williams for his commitment to “transparency and credibility.”

“The broader community’s engagement has been a textbook example of how a democracy should work,” McConnell said. “America is at its best when communities, like this one, lead from the bottom up.”

Destruction of Kentucky’s 520-ton (470-metric-tonne) stockpile began in 2019 after decades of planning and debate over how to dispose of the deadly war weapons. The Blue Grass Chemical Agent Destruction Pilot Plant, built with a single purpose of destroying the stockpile, was completed in 2015.

Workers disposed of VX, sarin and mustard agent loaded into projectiles that had been sitting in underground bunkers for decades. The last of the mustard agent was destroyed in 2021, and the final rocket containing VX agent was eliminated in April 2022.

The final remaining chemical weapon in the U.S., an M55 rocket tipped with sarin, was destroyed at the Kentucky plant in July.