Short answers, pulled from the story.
Harry McCarthy performed his new song for the first time in Jackson, Mississippi during the spring of 1861. He later played the piece again at the New Orleans Academy of Music in September 1861.
Major General Benjamin Butler ordered all copies of the sheet music destroyed and fined anyone caught singing or whistling the tune twenty-five dollars. This fine equated to roughly five hundred dollars in modern value.
Tennessee was the last state to depart from the Union on the 8th of June 1861. South Carolina actually seceded first on the 20th of December 1860 before other states followed.
Eleven other editions of the song appeared with different lyrics after the crackdown. Annie Chambers Ketchum published a version titled The Gathering Song under her own name while J.L. Geddes wrote a Union version in 1863.
The tune appears in the 1956 film The Searchers, the 1959 movie The Horse Soldiers, and the 1966 film The Good, the Bad and the Ugly. It also features in the 1972 television series Appointment with Destiny and the 1989 movie Glory.