There is a labor protest song about 23 boxcars but I can't find it.

In 1917, at the copper mines in Bisbee, AZ, some 2000 men went on strike; nearly all were Mexican, southern Italian, or Balkan. Threatened with deportation, 1186 refused to go back to work and, with the aid of Phelps-Dodge bosses, Cochise County officials and a large group of vigilantes, were loaded aboard 23 boxcars of the El Paso and Southwestern Railroad and shipped out of Bisbee.
About 15 hours later, near Hermanas, NM, the men jumped from the overloaded cars. They were abandoned, without food or water.
President Woodrow Wilson ordered the army to set up a camp for them at Columbus, NM.
Phelps-Dodge bosses, the sheriff and county officials and others were charged with conspiracy and kidnapping the following year, but were acquited. The copper companies gained control of Arizona politics.

I would very much appreciate the lyrics of the song, which I have been told is in the form of a corrido.

Some reforms were enacted when Mexican-American veterans returned after WW2 and unions again were allowed.

Thomas E. Sheridan, 1998, "A History of the Southwest, the Land and its People," p. 62ff. Western National Parks Association.
A book about the strike of 1983 discusses more recent conditions:
Jonathan D. Rosenbloom, 1999, "Copper Crucible: How the Arizona Miners' Strike of 1983 Recast Labor-Management Relations in America," Cornell University Press.
Also about labor and race in Arizona:
Philip J. Mellinger, 1995, "Race and Labor in Western Copper: The Fight for Equality, 1896-1918," Univ. Arizona Press.

At this time, Arizona is in the process of imposing very harsh illegal immigrant rules that seem to violate constitutional guarantees.