While the message remains clear enough, time has faded both the lettering and the memory of how it got there.
"Help End The War By Dec. 31, 1971. Join Common Cause," it says — a plea that now blends in seamlessly with the concrete-gray hues of Downtown's government buildings and the stop-and-go traffic on one-way streets, like an old tattoo that has faded into the skin.
While a $3.5 million renovation of the one-time bank building at North Stone Avenue and Alameda Street enhanced the sign's profile, Common Cause old-timers remain at a loss to explain where the message came from.
But as dated and worn as the sign may be, it is not going away.
At the urging of Tucson's Museum of Contemporary Art, the city Department of Transportation has decided to keep it, saying it has historic importance.
"Recognizing that we had an opportunity to preserve a piece of American history, we chose not to paint over the billboard," said Michael Graham, spokesman for the Transportation Department. "This goes back to Vietnam and some things that were happening politically."
Maybe so, but with wars raging in Iraq and Afghanistan, the sign with its anti-war message has fiery potential and relevance.
Common Cause, a nonprofit and nonpartisan advocacy group based in Washington, D.C., is best known for pushing for open government. Its slogan is "Holding Power Accountable." So at first glance, the anti-Vietnam War message seems an odd fit.
But in the early '70s, many people joined the group because it opposed the Vietnam War.
"A lot of us had gone through the '60s and ended up with nothing but an ongoing war," said Erik O'Dowd, a retired attorney who co-founded the Southern Arizona chapter of Common Cause in 1970.
That chapter is now defunct, but O'Dowd said the group's early members were split between what he called "intellectual" and "firebrand" activists.
Over the course of its first year, Common Cause met regularly, but no one ever mentioned painting an anti-war sign to advertise the group, O'Dowd said.
"In that first year, without any express authority from Common Cause, the sign got painted," he said. "It just went up."
O'Dowd doesn't know who painted it, but he said it touched off heavy debate within the chapter, with its already divided members.
For several weeks there was talk of having it painted over. Because it had been made without the group's consent, no one was sure if the message represented what the Southern Arizona chapter was really about.
But in the end "we decided it's great publicity," O'Dowd said.
And so the sign stayed up, at least for part of the early '70s, and maybe longer.
At some point, though — its unclear when — the sign was painted over, its message replaced with a large, black square set against a gray wall.
"That sign was obliterated," said Anne-Marie Russell, executive director of the Museum of Contemporary Art. "Someone blocked it out. It did not match. It was a black mark on a gray wall."
Over time though, the black paint faded and the message began to re-emerge — a process known as pentimento. It was not so prominent as to be obvious to the eye, but Russell said a person walking Downtown and paying close attention would see the letters.
She became aware of the sign a few years ago, and in the back of her mind, she said, she always thought about preserving it.
When the building renovation started, she decided to call the Transportation Department.
"We became concerned that through the renovation it might be painted over," she said.
And she was right. Had she called a day later, the sign would have been gone.
"I called literally the day before they were going to sandblast the wall," she said.
With wars raging in Iraq and Afghanistan, Russell said, she realized the sign's preservation might stir passions. But, she said, it is part of Tucson's history and should be preserved.
"I don't believe that it would be appropriate to censor an important relic of American history because it might make some people uncomfortable."
Sarah Hargis, whose husband is serving in Afghanistan, said she sees the sign as separate from the debate over the war in Iraq.
"It's a different war. It's a different time," she said. "I don't personally take any offense to it."
But Eugene "Wendell" Hague, commander of VFW Post 549, said he didn't understand what purpose the preservation serves.
"Probably most of the folks who would like to preserve this are the kinds who remember that type of anti-war sentiment from the '60s and '70s," he said.
In any event, the sign is staying, and Russell said she is hoping it will be permanently preserved.
"When it comes to preserving our history, it shouldn't be politicized," she said.
Did you know …
Tucson's main involvement in the Vietnam War stemmed from the fact that both the 4453rd Combat Crew Training Wing of the Tactical Air Command and the 355th Tactical Fighter Wing were based at Davis-Monthan Air Force Base.
Until it was transferred in October 1971, the 4453rd served as the training unit for some 6,000 Air Force pilots who went to Indochina.
The 355th probably suffered more casualties in Vietnam than any other Air Force unit because of its F-105 bombing missions over North Vietnam between 1965 and 1970, its public information officer told the Arizona Daily Star in 1975.
Also, the city's largest private employer, then called Hughes Aircraft Co., produced the Maverick missiles used in Vietnam.
The first widely heard local voice against the war was raised Oct. 22, 1967, by Rep. Morris K. Udall, in a speech before a prestigious group called the Sunday Evening Forum at the University of Arizona. "This nation has the brains, the know-how, the courage, the imagination to begin to extricate itself from a war we should never have blundered into," said the Tucson Democrat, who went on to run for president in 1976.
Protests turned intense in 1970.
For about 13 hours on May 5, 1970, students took over UA's Old Main, the center of campus ROTC activity. The next day some 50 students re-entered the building, and an American flag was burned. A protester later served a six-month federal prison sentence for that act.
Also on May 6, the work of the local Selective Service Board was interrupted by about 1,000 demonstrators.
By May 10, some 400 UA faculty members, about a third of the faculty, had signed petitions urging withdrawal from Cambodia and an end to the bombing of North Vietnam. On May 12, 16 protesters were arrested at another demonstration.
By the end of the war, Tucson had suffered 124 casualties in the war, not including 15 men listed then as missing in action, and eight local men were returned from POW camps.
Source: Star archives