If Jimmy cracks corn and no one cares why is there a song about it?

Answer 1

The original song, written around 1846 was used in reference to slave(s). If you read the lyrics

When I was young I used to wait
On master and hand him his plate
Pass him the bottle when he got dry (bottle referring to whiskey)
And brush away the blue-tail fly

Jimmy crack corn, and I don't care
Jimmy crack corn, and I don't care
Jimmy crack corn, and I don't care
My master's gone away

When he would ride in the afternoon
I'd follow him with my hickory broom
The pony being rather shy
When bitten by the blue-tail fly

Chorus

One day he rode around the farm
Flies so numerous that they did swarm
One chanced to bite him on the thigh
The devil take the blue-tail fly

Chorus

Well the pony jumped, he start, he pitch
He threw my master in the ditch
He died and the jury wondered why
The verdict was the blue-tail fly

Chorus

Now he lies beneath the 'simmon tree
His epitaph is there to see
"Beneath this stone I'm forced to lie
The victim of the blue-tail fly"

There are other slight indications, how he used to follow the "master" with a broom to shoo the blue tail flies away and keep them from biting the master or the horse. The next course speaking of his master on a horse has a couple of implications,

One day he rode around the farm,
flies so numerous they did swarm
one chance to bite him on the thigh
the devil take the blue tail fly.

With this it appears that the fly bit the horse, which of course hurt, with the sentence "the devil take the blue tail fly" it appears that either the slave or the master hit the fly killing it, thus causing the horse to buck (Jump, start, pitch in the next verse). In the long run the master was killed. However, with the next verse, "the jury wondered why", gives implication that the child may have "hit" the horse with the broom and caused the horse to buck, but with out the proper evidence, "the verdict was the blue tail fly."

Cracked corn referred to Moon-shine (or some form of whiskey), which was made from " corn ", so the cracked corn is the consuming of the whiskey in celebration that their master was dead.

It's obvious that the "Jimmy" is not referring to the "singer" or "writer" of the song, but perhaps the father of the child in the first verse or another slave.

Answer 2

Perhaps the author of the song wanted to make their apathy on the subject definitively known, or was just bored and needed a topic for their musical inspiration.