Here is a list (with links) of the majority, concurring and dissenting opinions on church-state, religious freedom and religious discrimination issues that Justice Souter has written during his 19 years on the Court.
Majority opinions:
- McCreary County v. ACLU, 545 U.S. 844 (2005).
- Edelman v. Lynchburg College, 535 U.S. 106 (2002).
- Board of Education of Kiryas Joel v. Grumet, 114 S. Ct. 2481 (1994).
- Pleasant Grove City v. Summum, 129 S. Ct. 1125 (2009).
- Capitol Square Review & Advisory Board v. Pinette, 515 U.S. 753 (1995).
- Church of Lukumi Babalu Aye v. City of Hialeah, 508 U.S. 520 (1993).
- International Society for Krishna Consciousness v. Lee, 505 U.S. 672 (1992).
- Lee v. Weisman, 505 U.S. 577 (1992).
- Hein v. Freedom From Religion Foundation, 551 U.S. 587 (2007).
- Van Orden v. Perry, 545 U.S. 677 (2005).
- Zelman v. Simmons-Harris, 536 U.S. 639 (2002).
- Good News Club v. Milford Central School, 533 U.S. 98 (2001).
- Mitchell v. Helms, 530 U.S. 793 (2000).
- Agostini v. Felton, 521 U.S. 203 (1997).
- Rosenberger v. Rector & Visitors of the University of Virginia, 515 U.S. 819 (1995).
(Please let me know of any omissions in the list.) [Updated.] [Thanks to Ed Elfrink and Kevin Pybas for additions.]