Even more popular that Stephen Foster during his time, Henry Clay Work wrote many songs that captured the spirit and struggle of the Civil War. George F. Root described Work as "a slow, painstaking writer, being from one to three weeks upon a song; but when the work was done it was like a piece of fine mosaic, especially in the fitting of words to music." (ArchivMusik.com)
Photo: Henry Clay Work, public domain
Born in Hartford, Connecticut to abolitionist parents, Work taught himself songwriting after he apprenticed for a printer. In 1855, he moved to Chicago to work for the publishers Root & Cady.
Work wrote his most popular and well-loved songs during the Civil War, including "Kingdom Coming" and "Uncle Joe’s ‘Hail Columbia!’" (both from 1862), as well as "Marching Through Georgia" (1865), a Union song celebrating the victory of Sherman's March. Work's song output also includes love songs and moralistic, tragic, and humorous pieces of music. After the Civil War ended, Work's popularity died down, though it revived again in 1875 with his song "Grandfather's Clock," which reached an unprecedented sales of almost one million copies.
Source: New Grove Dictionary of Music and Musicians