Prof. Michael Marder of the University of Texas at Austin shows in a simple way (but with a lot of behind-the-scenes work) how American education has been steadily improving. The chart below shows the state-by-state improvement in 8th grade math scores. New Hampshire (blue, 8 points between 2003 and 2009) and Massachusetts (green, 21 points between 2000 and 2009) improvements are highlighted. Click on the graph for a little video explaining what you are seeing.
But, even more impressive, here is the live version of the chart. You can manipulate it in any way you want in order to review a variety of types of state-by-state education data over the period from 2000 to 2009.
Updated 5/27/12, 9:40am to make the degree of improvement clearer.