Like many, I have tried to find further background on Longstreet leaving Protestantism and entering into full communion with the Roman Catholic Church. As Catholic’s were a distinct religious minority during the CW period and many were the target of ante bellium prejudice and persecution by the Know Nothing Party, it seems remarkable that Longstreet would make the change from Episcopalian to Roman Catholic. My search lead me to first consider other men and women of the Civil War period that either became Catholic , or were themselves Catholic.
The main figures, of course are Sheridan, Sherman’s wife and his son (who became a Priest), P.G.T. Beauregard and Rosecrans. As a side, Jefferson Davis as youngster asked to be Baptized as a Catholic but was denied the request because of his young age and the Jesuits would not do so without the request and permission of his Parents.
The key to understanding Longstreet’s conversion may very well be Rosecrans. The two were roommates at West Point. William was an outstanding student. Longstreet was an average student so Rosey was his math tutor. Both graduated in the class of 1842. Keep that date in mind.
In his first year at West Point , Rosecrans was having serious doubts regarding the proofs and claims of his Methodist Protestant faith and nearly abandoned his Christianity altogether. He came to meet a Catholic Irish bookseller. The bookseller and William developed a relationship around religious questions. By this relationship Rosecrans came into possession of a book published in England called “The End of Religious Controversy” by a Priest named John Milner published in1844. The book was a series of letters from Anglicans to the Catholic Priest asking for explanations on why the Catholic Church is the one true Church. By the time Rosecrans would have read it the Oxford movement in England was setting forth it’s first shoots. It’s a most interesting read :
http://www.balderexlibris.com/index.php?post/Milner-John-The-End-of-religious-controversy
Rosecrans became Catholic after reading the book. He was so impacted by this that he shared it with his Brother Sylvester. Sylvester not only became Catholic but he became a Priest and was appoint as the First Bishop of Columbus Ohio. Two the Rosecrans sites were converted and became Nuns. Really remarkable for a Methodist family in Ohio.
Here is where the link to Longstreet comes in. Rosecrans wrote a letter on December 11,1886 regarding his brothers Baptism and reception into the Church.
http://rosecransheadquarters.org/Rosecrans/Crandall Family/Sylvester.htm
In it, William states that his own Catholic Baptism was in 1841. This would have been the year before the Longstreet / Rosecrans graduation of 1842 and when they were roommates. Though it can’t be proven by records it’s almost certain that the two roommates would have discussed Williams Baptism and conversion and the contents of the Milner book. Perhaps Longstreet may have even read Williams copy. Rosecrans was known to be very outspoken on this topic so if anything Longstreet might have gotten more than he wanted on Catholic theology.
Then war calls and the friends are on opposite sides.
Fast forward to Chickamauga twenty two years later Longstreet is now facing his Catholic convert roommate in battle. And shortley after that Longstreet is wounded at the Wilderness by the army led by Grant. Longstreet was in Grant's wedding and a cousin to Grant's wife. One can only imagine what would have been going through his mind. Also consider the loss of his young children from his first wife and the role that would have played in his faith journey. These life events play into the soul of men's lives.
I for one find it difficult to believe a man of Longstreets character and depth would make a major life altering decision to enter into full communion with the Roman Church simply because his feelings were hurt by his friends and neighbors at the Protestant Church he attended. His post war behavior showed the opinion of others did not move or alter his decision much. Was he really so shallow as to have no theological apologetic to make this decision?
It’s not unreasonable to conjecture that his exposure to young Rosecrans passionate and meaningful conversion at West Point and the apologetic in the Milnar book planted seeds in the young Longstreet that grew for decades under the surface and finally , moved by the life experience of prayer , wounds, death, and post war events the Old War Horse swam the Tiber to Rome.