It seems like the verse of "We Shall See Her No More" (from American Memory Collection) is the origin of "Sweet/Bright Sunny South." No one really had any detailed older info about it in the DT. What do you think?

WE SHALL SEE HER NO MORE
Words By C. Hart; Music By F. Buckley
Publisher: Philadelphia, Pennsylvania: George S. Harris
American Song Sheets, Series 1, Volume 10

Oh, the bright sunny South, where the sugar cane grows,
And the cotton flow'rs gracefully bend in the wind
Where life, like a dream, full of happiness flows,
And Massa, dear massa, was always so kind;
Oh, yes, it was there in the south that I met
With sweet Lilla, the pride of my heart,
And the joy that I felt I can never forget,
Till the last spark of life from my bosom shall part.

CHORUS--But now she has gone,
And her sweet life is o'er,
We shall see her no more,
We shall see her no more.

How often at eve, when our labours were o'er,
We roved where the river ran swiftly along,
And often we sat on the blossoming shore
To list to the Mocking bird's rapturous song.
Oh, yes, it was there in the bright Southern land,
By the river side under the old shady tree,
As we sat all alone in the sunset so grand,
That dear little Lilla was plighted to me.

-Richie