Samuel Davies (1723-1761) was both a poet and an early American advocate of singing uninspired hymns in public worship - in fact, he was the first American-born hymn-writer. A minister who read and appreciated the The Psalms of David Imitated by Isaac Watts, he frequently gave away copies of Watt's hymnal to others. Davies himself composed a total of 18 hymns, two of which were variations on compositions produced by Philip Doddridge. The other sixteen were published in one volume, though scattered amongst other compositions, posthumously by his friend Thomas Gibbons in 1769, under the title Hymns Adapted to Divine Worship. We have extracted those hymns by Davies from that volume at Log College Press.
Louis FitzGerald Benson (1855-1930) also wrote two fascinating articles about Samuel Davies, the hymn-writer, in the Journal of the Presbyterian Historical Society: "President Davies as a Hymn Writer;" and "The Hymns of President Davies." His analysis of the background of these hymns is extremely helpful to those concerned to know more about the context of these hymns, which were often written by Davies to accompany a particular sermon upon which he preached. The latter article reproduces not only the 16 original compositions by Davies, but also the 2 variations on Doddridge.
If you wish to learn more about the compositions of "America's Isaac Watts," these primary and secondary sources will be of great help.