The property known as La Paz that President Obama will visit Monday has come a long way since the days when the Cesar Chavez Foundation had to buy it in secret.

The 187-acre Keene area property that Obama last week declared a National Historic Monument was built in 1929 as Stony Brook Retreat, a sanitarium for tuberculosis patients.

United Farm Workers wanted to buy the county-owned campus to establish the Nuestra Senora Reina de la Paz Educational Retreat Center, but was afraid grower-friendly county officials wouldn't sell to them. In 1970, a wealthy, sympathetic Hollywood movie producer bought it and immediately sold it to the organization that is now the foundation for $1.

Nuestra Senora Reina de la Paz (Our Lady, Queen of Peace) -- or La Paz, for short -- is in the Tehachapi Mountains just north of Keene and consists of 26 historic buildings, as well as the Cesar Chavez Memorial Garden, where UFW co-founder Cesar Chavez is buried.

The union chose the property in part because of its distance from the union's first headquarters site in Delano, said longtime UFW spokesman Marc Grossman, who lived and worked at La Paz for several years along with Chavez and other staff and volunteers.

"Cesar was afraid that if the headquarters was out there, the workers would always come to him instead of developing their own indigenous leadership," Grossman said.

Like the farm worker movement's previous headquarters on the Delano property known as Forty Acres, La Paz was a hub of social and political activism.

"From its inception in 1962, UFW was much more than a union," Grossman said.

"Because the dilemmas facing farm workers were so daunting -- working conditions, pay, housing, lack of educational opportunities, health care -- Cesar modeled the UFW after the unions of the early 20th century that offered English classes and social services," he said.

So La Paz had classrooms where activists learned how to organize workers and negotiate contracts, meeting rooms for planning, small homes for families and dormitories for singles.

It seemed like every other weekend there was a wedding there, Grossman said. Nobody had any money back then, so the union provided couples with a venue, a band or a D.J., dinner and some wedding presents.

Ray Gonzales, a former farm worker who won a seat in the California Assembly in 1972, recalls speaking with union leaders at La Paz when he was running for office. At the time, the union was widely viewed as radical and dangerous.

"They asked what they could do to help," he said. "I told them, 'Whatever you do, don't endorse me. I need your troops, but don't endorse me publicly."

The UFW's current president, Arturo Rodriguez, lived on the campus for a time and still resides in a home he purchased nearby.

He has fond memories of raising children at La Paz.

"It's the biggest playground you could ever imagine," Rodriguez said.

Today, the campus is widely recognized as a special, even spiritual place where people come to pay their respects to Chavez and all that he stood for, Rodriguez added.

"It's far beyond just a bunch of union buildings," he said. "People come from all over the world to visit because it's about respect, human dignity, self respect and social justice throughout the world."

The foundation, which owns both La Paz and Forty Acres, will donate a portion of La Paz to the federal government for the establishment of the monument, which will include a visitors center containing Cesar Chavez's office, UFW legal aid offices, the home of Cesar and Helen Chavez and the Chavez Memorial Garden containing Chavez's grave site, among other things.

The UFW will still use the buildings it now operates in, however. And Chavez's widow, who still lives in the modest, two-bedroom home the couple shared when he lived, will be welcome to stay in her home for the rest of her life.