The Child's Wish. American Tract Society handbill. [New York]: [American Tract Society], .
Handbill, 4 1/4 x 7 3/4 inches, center fold, watermark bottom right corner. Hymn in four stanzas, with ornamental border. Small ink smudge top margin edge. With no imprint, and it appearing in print from several publishers in hymnals, the attribution is an educated guess. Good. Handbill. 
This is listed in the Forty-third Annual Report of the American Tracts Society (1857) as their handbill, no. 99. It is a song for sick and dying children. There is a WorldCat entry (no. 191274615) but it differs from this printing. Worldcat matches the ATS attribution above, but this copy does not have the number 99 printed on it. Worldcat holdings are all internet resource, and not printed copies.
Written at a time when the death of children was a frequent occurrence, this song has the child singing that they want to be an angel, gathering with the angels in heaven to sing the Saviour's praise. The first line is, "I want to be an angel."
Part of one stanza is "I know I'm weak and sinful | But Jesus will forgive | For many little children | Have gone to heaven to live." The tune suggested for the song is "Watcher."
We also find this song in Gospel Hymns, by James H. Brooks, published by The Old School Presbyterian in St. Louis, 1871. It perhaps appears in other hymnals as well.