American Catholic Studies, the journal of the American Catholic Historical Society, has published a history of Pax Christi USA as the cover story of its most recent issue (Volume 133, No. 4).
Use this link to download and save a PDF version of the article.

The American Catholic Historical Society (ACHS) was founded in 1884 for the purpose of collecting and preserving materials relating to U.S. history and the contributions of Catholics to the building of the country, as well as the Catholic Church in the United States. It is the oldest historical organization of its kind in the United States.