edit - Just looked at budgets. You are picking the peak. Which makes me somewhat doubtful of the rest of your analysis. In 2009 it was $32 billion. In 2010 it was $56 billion. It peaked at $71 billion in 2011 and has been almost flat since then.
edit2 - heh, actually the peak was in 2009. Do not trust wikipedia. http://chart.googleapis.com/chart?chtt=Department+of+Educati... http://febp.newamerica.net/background-analysis/education-fed...
Still, the general point holds, it has not been remotely steady at $70 billion.
Appropriations since 1980 add up to about $1.334 trillion. This is not inflation adjusted, however, so the equivalent amount in 2014 dollars would be much higher.
I wish they had given NASA that money instead and maybe we'd have a colony on the moon by now.
Also, you have given no references whatsoever for your claimed steady decline in literacy and maths since 1979.
The decline in literacy and math scores is well documented.