Joe Nick - from slave to Civil War soldier

During the Civil War, Joe Nick drove a pair of horses with a covered wagon from his master Reuben Rogers' ("a lawyer and farmer") farm to join the Union Army.  In Ellicott City he hopped aboard a freight train going west.  Nick returned in uniform in June 1865, and Rogers had him put in the EC jail as a fugitive slave. The US Marshall freed Nick and arrested Rogers.  The story was retold by "the younger generation" as "Old Nick: Rogers lemon."

But. There are some questions about the story.