H. De Marsan published and sold songs, books, and toys in New York City during the later 19th century. Located on what is now Park Row in lower Manhattan, the publisher was likely active in the later 1800s, throughout and following the American Civil War from 1861-1865. Many of the songs published by H. De Marsan uplift Irish soldiers, generals, and brigades fighting for the Union during the American Civil War. While songs such as ‘Long Live the Sixty-Ninth’, and ‘Jeff Davis’ are firmly Unionist and mourn the violence of war, the songs serve to instill pride at the fortitude and skill of Irish soldiers rather than engage with the United States’ legacy of slavery. Laments published by H. De Marsan further contributed to the developement of a national Irish-American identity tethered to the irreconcilable longing for home with songs such as ‘The Girl I Left Behind Me’.