Colportage is the distribution of publications, books, religious tracts, etc., by carriers called "colporteurs".
The term is an alteration of French comporter, "to peddle" as a portmanteau or pun with the word col (Latin collum, "neck"), with the resulting meaning "to carry on one's neck". Porter, is from Latin portare, "to carry."
"Christ in the Camp", by Dr. J. William Jones, often refers to the Chaplains carrying Bibles and tracts as Colporters. Part of their work was distributing literature, as well as public preaching in the Southern Army, namely the Army of Northern Virginia. The American Bible Society and the American Tract Society were among the largest organizations involved in colportage in the United States. The Seventh-day Adventist Church currently use the title "Literature Evangelist" for their book distributors. "Colporteur" was the title used until about 1980.
The term may also be seen referring to any kind of book peddling, not only the religious ones.