Ms. Armstrong serves on the board of the Great Rivers Environmental Law Center, and the American Civil Liberties Union of Eastern Missouri. She was appointed in 1999 to serve on the Citizens Advisory Committee for Corrections for the state of Missouri. She is currently serving in this capacity.

Ms. Armstrong was the Executive Director of the American Civil Liberties Union of Eastern Missouri from 1971-1997. In that capacity she served as the organization's chief spokesperson, and has received numerous awards for her service in civil liberties and the humanities. Ms. Armstrong has written on topics concerning juveniles, students' rights, privacy, civil rights, civil liberties, legislation, and federal and state laws. As adjunct Professor of Political Science she also taught courses on civil liberties at the University of Missouri-St. Louis.