Conservatives have long complained about schools' use of Howard Zinn's A People's History of the United States. But, a popular AP U.S. History textbook, The American Pageant, written by Thomas Bailey, David Kennedy, and Lizabeth Cohen, is also riddled with inaccuracies. That's according to Daniel Oliver, chairman of the board of the Education and Research Institute.

“Almost every other page” has liberal bias, Oliver charged during an interview with Townhall on Tuesday.

His "favorite" example, he said, is the book's section on Alger Hiss. It's well known that Hiss was a communist who was supplying information to the Soviet Union, Oliver relayed. He was convicted of perjury in 1948. Yet, in The American Pageant, the authors write that Hiss was being chased by Richard Nixon, a “red hunter,” and that he got caught in “embarrassing falsehoods.”

Oliver calls the description "extraordinary" and "ridiculous."

"He was a communist," Oliver said. "But the left decided to take the position that he was not."

Oliver and his team expose what they believe are other misinterpretations in trueamericanhistory.us. For instance, they note how the authors praise Franklin Delano Roosevelt as "suave and conciliatory" and a "master politician," while avoiding how he "often tried to initiate and use government subsidies to win targeted voting groups, which ran up the national debt to record amounts" and "had trouble telling the truth," ERI writes.

The left wing bent found in many of American history textbooks can be traced to the post-World War Two era, when progressive scholars from Germany who came to the U.S. infused their progressive politics into the education system. Making a mark on education is an "effective" way to change a culture, Oliver noted.

Parents don't always have the option, or the time, to fight back against school boards. So, what's the solution? In addition to reading the critiques on trueamericanhistory.us, Oliver suggests students read Bill Bennett's two-volume history book. There are plenty others that are "sane" and "sound," Oliver said.

It's also up to public institutions like ERI to "come in and raise a ruckus so that school boards will pick better textbooks."

He doubled down on the need to disrupt school board appointments. Those, he said, are "a good time to stage a fight to get people who will teach history the way it should be taught."