The genesis of this song is discussed by Olive Woolley Burt in her 1958 Oxford University Press book American Murder Ballads And Their Stories
. Written in 2/4 time, "The Hennessy Murder" was collected by Burt's husband.
On October 15, 1890, New Orleans police chief David Hennessy
was gunned down in what was if not the first then the first widely publicized Mafia murder in the United States. Hennessy's dying words were "The Dagos did it!" According to Burt, eight Italians were arrested and held for trial, "but the frenzied citizens stormed the jail, extracted the prisoners, and hanged them all [from] convenient trees."
In fact, the aftermath of Hennessy's murder was a little more complicated than that; the assassination resulted in mass arrests of Italians, and a Grand Jury indicted no less than 19 men of Italian origin (including alleged members of two gangs); nine men eventually stood trial. The proceedings were both tainted and farcical; all nine walked free, but the good people of New Orleans decided to take matters into their own hands.
None of the lynchers was ever indicted for the crime, and for a time there was even talk of war between the United States and Italy.
Surprisingly, Hennessy had himself been tried for murder, in 1882, but was found not guilty on the grounds of self-defense.
Alexander Baron - London, England