The Southern Harmony as listed here shows a publication date of 1835. I understand that was the date of the first edition, but there were a few revisions until 1854. I can't find the copyright page, or any page showing dates, in the page scans of the edition shown here. The reason why I question the date 1835 is because the index here includes Happy Land, which is asserted to be written by Andrew Young in 1838. And at least one other source asserts the tune was arranged by Breedlove in 1850.