Public school teachers have been among the loudest voices protesting inside and outside the Wisconsin state capitol in Madison over Gov. Scott Walker's proposals for dealing with the state’s budget problems - specifically his legislation to limit public workers' collective bargaining rights.

Here’s a piece of irony: Wisconsin law requires that public school students be taught the history of organized labor. The kids certainly are getting a real-time lesson in the subject.

Some teachers who left their classrooms and hit the bricks in defense of their ability to organize and negotiate contracts likely are those who teach the history of the labor movement to students in those same classrooms.

Wisconsin Assembly Bill 172, passed by Democrat-controlled state legislature, was signed into law by then-Gov. Jim Doyle, a Democrat, in December 2009.

The law requires teachers to include instruction in “the history of organized labor and the collective bargaining process.”

The state’s Department of Public Instruction website reads: “Wisconsin has long been a leader in labor rights. The Progressive Movement, which had its beginnings in our state, led to laws limiting child labor and safety in the workplace. Unions such as the AFL-CIO and Teamsters allow us to enjoy an eight-hour work week and vacation time. In fact, it has been argued by some historians that the history of the United States itself could be a history of labor.” The DPI site notes that the law made Wisconsin the first state in the nation to include the history of organized labor as part of state standards for teaching social studies.

Teachers are referred to websites for the Educational Communications Board Surf Report on Labor History, Wisconsin Historical Society Labor Collections and Wisconsin Labor History Society.

The Wisconsin Labor History Society offers teachers outlines to help them present the subject. “Workers and unions helped to make our nation great and to create our standard of living, with top wages and benefits for all workers. There were many struggles facing workers in reaching these goals. This presentation will discuss some of those struggles and identify the major gains of early workers and their unions. ...

Today, the United States is the richest country on earth. By most standards, U.S. earnings permit the vast majority of us to enjoy the highest standards of living. Most families have cars, sometimes two or three, televisions, refrigerators and their children have access to boom boxes, CDs, computers and cell phones.”

Back in April 2009, when then-historical society President Kenneth Germanson testified before the state legislature in support of the bill, he recounted the contributions by organized labor to American society. “But who is aware of this today?” Germanson asked. “Very few persons, and it’s a result of an education system that has overlooked a key part of American history. It’s precisely this omission that AB 172 seeks to overcome.”

Some politically conservative blogs are now calling to repeal AB 172.