The Enfields came over complete with a bayonet. The Enfields the US bought were probably issued with the enfield bayonet. Uncle Sam is like that.

Confederates picked up many Springfields and probably an Enfield or two off of the battlefields. These arms were inspected, repaired if necessary and issued to the troops. The Confederate Quartermaster in Richmond had socket bayonets made for the army and some of Lee's soldiers had these bayonets issued as replacements.I would suspect that the same would hold true for these bayonets, that they would fit an Enfield or Springfield. If you noticed on my page, there is an Enfield scabbard throat that has been modified to accept a Springfield bayonet. The leather M-55 scabbards didn't have a metal throat and didn't need any modification. Basically CS soldiers didn't worry about which bayonet they had, as long as it fit and neither did their officers. The Quartermaster was more worried about supplying bayonets for all the soldiers as they had a habit of losing them.