In 1945, Davis Wallis was a 22-year-old photographer assigned to the 168th Signal Photo Company documenting the movement of American troops as they crossed the Rhine River in Germany.
   
As soldiers stopped to rest for the night, Wallis noticed a tarp covering a large container full of munitions stamped "PBA."
   
The Pine Bluff native knew immediately that the shells — stuffed with a deadly nerve agent — had been produced at the Pine Bluff Arsenal, then a 4-year-old installation.
   
"A general told me that they had heard the Germans had a powerful nerve gas they had planned to use on us," said Wallis, Pine Bluff’s mayor from 1980-84. "What they didn’t know was that we had something better."
   
Wallis firmly believes that the weapons’ presence discouraged chemical warfare that night near the Rhine River.
   
Thousands of similar weapons never even made it to the battlefield. Instead, they were stashed at eight stockpile sites around the United States, and later were joined by an even deadlier generation of munitions designed to deter the growing Soviet threat.
   
The deadliest of the poisons in the relic munitions were forged primarily at two places: Colorado’s Rocky Mountain Arsenal and the Wabash River Ordnance Works in Newport, Ind.
   
Not long after the 1941 attack on Pearl Harbor, construction of the Rocky Mountain Arsenal began on 19,000 acres of farmland east of Denver. Some of the earliest toxins that rolled off the production line included chlorine gas, Lewisite and mustard gas.
   
At the time, mustard gas was the poison of choice for chemical warfare. Used by the Germans, French and British during World War I to paralyze enemies, mustard gas ultimately killed by eating away the lining of soldiers’ throats, causing them to choke to death.
   
But mustard gas’s popularity diminished with the discovery of GB (also known as Sarin) by German scientists trying to invent a powerful insecticide. Instead, what they ended up with was a chemical agent about 500 times more lethal than cyanide.
   
"They [the Germans] had a rule back then that anyone working with toxic chemicals had to show their product to the military to see if they could use it," said Jeff Smart, historian with the U.S. Army’s Research, Development and Engineering Command.
   
As the fear of a Soviet attack intensified, so did the evolution of deadlier chemical agents. GB was replaced by VX, a toxin so deadly that an amount the size of a pinhead could kill a 180-pound man in a matter of minutes.
   
VX was produced at the Wabash River Ordnance Works beginning in 1961, although most of the nation was unaware that the nerve agent existed.
   
However, its deadly existence become well known in 1968 when more than 3,000 sheep were accidentally killed in the Utah desert during top-secret experiments at the Dugway Proving Ground.
   
The bad press generated from the dead sheep combined with increased criticism about the use of defoliants in Vietnam led President Nixon to issue a series of orders in 1969 that virtually ceased production of all chemical and biological warfare agents.
   
"I think that the Nixon decision marked a crucial point, but the decision to cease productions was also influenced by the fact that the Army met the requirements for what was needed for a national stockpile," Smart said.
   
He pointed out that while the Nixon orders spurred formal demilitarization, the military had actually been destroying chemical-filled munitions since World War II.
   
Suspected duds or weapons captured from the Germans and Japanese were carted out to sea where they were dumped. At other times, a barge carrying the weapons was taken out to sea and deliberately sunk.
   
Smart said "offshore disposal" was the generally accepted elimination method until 1970 when public outrage put an end to the Cut Holes and Sink ’Em program.
   
"Studies showed that applied pressure on the containers would cause the weapons to implode underwater," Smart said. "And then the seawater would rush in and render them inert."
   
In 1985, Congress issued its first directive to begin destroying the stockpiled weapons, launching the current chemical weapons destruction program.
   
Today, weapons destruction is overseen by the U.S. Army’s Chemical Materials Agency.
   
"As with any program — and I know this is a cliche — but we’ve come a long way baby," said Greg Mahall, an agency spokesman.