Have you been pursuing a possible Kilkenny (Ireland) connection.
Langtons are well established in Kilkenny - since 1485 and the Stephens name was also well known in Kilkenny in the 19th century
30 years after the wedding you mention, this appeared in a Kilkenny newspaper on August 19, 1848 when the Kilkenny Moderator in its obituary column wrote:
“Poor James Stephens who followed Smith O’Brien to the field, has died of a wound which he received at Ballingarry whilst acting as aide-de-camp to the insurgent leader. Mr Stephens was a very amiable, apart from politics, a most inoffensive young man, possessed of a great deal of talent, and we believe he was a most excellent son and brother. His untimely and melancholy fate will be much regretted by a numerous circle of friends.”
James Stephens father was a clerk in a well-known and much respected Kilkenny establishment, of auctioneers and booksellers. He gave his family a decent living and a good education and enrolled his son James in a Catholic seminary for the purpose of making him a priest. But James thought he could best serve God, by fighting for his country.