Here's a complete digitization of Samuel Wakefield's Christian's Harp, "corrected, enlarged, and much improved by Lazarus B. M'Lain". This shape-note tune book was published in Pittsburgh by Johnston & Stockton, 37 Market Street, in 1837.
For fun, I've linked to page 25, where you'll find a tune called Pittsburgh. You can page through the book by clicking on the left- or right-hand page of the image. Or use the toolbar.
In these three-part arrangements, the melody is on the top line. Shape-note singers will find quite a few familiar tunes here. Idumia [sic], for instance, is on page 47 of the appendix, and Sherburne on the next page.