How has the legal system evolved, as it applies to special education over the past 20 years?

It's not our jobs to write your essay for you. If you want to learn about education policy in the past 20 years, I recommend you start with some of the following titles: Meier, Kenneth J., J.L. Polinard, and Robert D. Wrinkle. Bureaucracy and Organizational Performance: Causality Arguments About Public Schools. American Journal of Political Science. Vol. 44, No. 3, July 2000. Rouse, Cecilia Elena. School Reform in the 21st Century: A Look at the Effect of Class Size and School Vouchers on the Academic Achievement of Minority Students. Working Paper #440, Princeton University, Industrial Relations Section, June 2000. McGee, Robert W. A Solution to the Education Crisis. Dumont, NJ: The Dumont Institute for Public Policy Research, July 1996. You can use JSTOR or another database to back-search articles citing these sources. Good luck.

That is not research,, it is plagiarism. You need to do your research the traditional way.