In reverse order- it does seem that this is the same Sweeney, but I haven't looked it up.
Here is the entire song, which doesn't say whether he was hauling coal or charcoal with his steers and cart. It sheds light on the times (1840) and is more of a "story" song than most minstrel pieces.

Lyr. Add: JONNY BOKER OR THE BROKEN YOKE

As I went up to Lynchburg town,
I broke my yoke on de coaling ground;
I drove from dare to bowling spring,
And I tried for to mend my yoke and ring.

Chorus:
O Jonny Boker, help dat nigger do,
Jonny Boker, do.

I drove from dare to Wright's ole shop
Hollered to my driver and told him to stop;
Says I, Mr Wright, have you got a yoke?
He seized his bellows and blew up a smoke
O Jonny Boker, etc.

Says I, Mr Wright, habn't long to stay
He cotched up his hammer, knocked right away;
Soon as he mended my staple and ring
Says I, Mr Wright, do you charge any thing?
O Jonny Boker, etc.

Says he to me I neber charge
Unless de job is werry large;
For little jobs dat is so small
I neber charge any ting at all
O Jonny Boker, etc.
(Save three cents dat time)

I drove from dar to Anthony's mill
And tried to pull up dat are hill
I whipped my steers and pushed my cart
But all I could do, I couldn't make a start
O Jonny Boker, etc.
(Dat ole nigger was fast stalled dat time)

I put my shoulder to the wheel
Upon de ground I placed my heel;
Den we make a mighty strain
But all our efforts prove in vain
O Jonny Boker, etc.

Dare come a waggoner driving by
I sat on de ground and 'gan to cry;
Says me to him some pity take
And help me up for conscience sake
O Jonny Boker, etc.

Says he to me, I will help thee
He tak out his horses No. 3;
I wiped from my eyes the falling tears
He hitched his horses before my steers
O Jonny Boker, etc.,

Den to me he did much please
He pulled me up with so much ease
His horses were so big and strong
De way dey pulled dis nigger along
O Jonny Boker, etc.

@minstrel @work
Details on publication are given by Masato Sakurai, in a post above, with a click to the Levy Collection where the sheet music is shown.