Where can I get a list of federal court cases?

I have to do a timeline for Tinker v. Des Moines. THe case occured in 1969 before the Supreme Court. I have to make a timeline of lower court cases that related to this issue of students rights that occured before 1969. ANy suggestions of sites?Where can I get a list of federal court cases?
The best way to find the cases preceding Tinker is to read Tinker itself and see what cases the court cites. Probably even better would be the lower court opinion in Tinker. Those opinions will give you a good start. Also, get a copy of the briefs that the parties filed -- they will cite most of the significant cases on the subject. You can usually get the briefs online at lexis.com -- just type in the citation of the case and they will offer to show you the briefs, as well as the court decision. Unfortunately, lexis.com isn't free -- in fact it is very expensive. You might be able to find the briefs elsewhere -- check with a research librarian at the local public library or law library.