For both the USCCB and Diocese of Manchester websites, there are so many references that it is hard to spend that much time sorting through them, and navigate their web sites. The below is a short list of key documents, with links so that you can access them easily.

Pope St. John Paul II: The Gospel of Life (Evangelium Vitae) (1995 Encyclical)
Click here to read the full document.

USCCB: Living the Gospel of Life: A Challenge to American Catholics (December 1998)
Click here to read the full document.

USCCB: Happy are Those Who Are Called to His Supper (November 2006)
Click here to read the full document.

USCCB: Forming Consciences for Faithful Citizenship: A Call to Political Responsibility (November 2007)
Click here to read the full document.

USCCB: Catholics in Political Life
Click here to read the full document.

USCCB: Life Issues Forum
This is a bi-weekly publication of articles by the USCCB Secretariat of Pro-life activities, covering just about any topic you can think of.
Click here to access the forum.