M'Cauley, E. D. The Harmonia Unio: being a collection of Psalm and Hymn Tunes, Anthems, &c., &c. with An Appendix of the most Approved Standard German Church Tunes, designed for Singing-Schools, Choirs, Congregations, &c. Philadelphia: Henry B. Ashmead, 1858. 
Leather spine with printed peach paper boards, some loss of leather yet with good joints, covers scuffed and worn with some loss of paper, oblong 15 cm (6 x 9 1/2 inches). (1)-114, 119-120 pp. Defective: lacking 2 leaves (pp. 115-118) and the rear free end papers. Many leaves with tattered margins. Fair. Hardcover.
The publisher's building on George Street above Eleventh, Philadelphia, is illustrated on the back cover.
7-note shape-note system. The author hailed from Fredericksburg, Pennsylvania.