They did give standardized tests in many schools previously, but they did not give then nationally for the purpose of rating schools.
I took those Iowa tests too, but I never saw any results, not of my performance, nor of the school's performance. The results were not published in any newspaper that I ever saw.
Whatever the results of those tests were used for, it was done entirely behind the scenes. I never heard that they were changing a single element of the curriculum based on test results, or even selecting a different textbook for any class.