The red, white and blue Star-Spangled Banner has long been a symbol of patriotism in the United States, and by the mid-19th century, envelopes adorned with patriotic symbols began to find their way into Americans' mail boxes. Civil War envelopes showing the flag with 34 stars, used by the Union to illustrate its rejection of the Confederacy's secession and to signify the constancy of the Union. With message and lyrics such as, “Not a Star Must Fall,” and “we must keep the Flag where it e’er has stood,” these envelopes filled the country with pro-Union propaganda. Conversely, the Confederacy used phrases such as “Liberty or Death,” and “Southern Independence” to support the division of the country. Images of Jefferson Davis were paired with lyrics such as, “stand firmly by your cannon. Let ball and grape-shot fly. Trust in God and Davis, and keep your Powder dry,” instead of poems praising the Union and the Star-Spangled Banner.
In 1943, an article in American Collector explained that the flags first appeared in the mid-1850s, and were indeed used for mail, but by 1861, the envelopes had become collectors' items. There was even a book for sale that would hold 100 illustrated envelopes.
During the Civil War, over 15,000 different patriotic envelopes were published, most of them pro-Union. More than 100 known printers in 39 cities created them, and some northern printers even made early Confederate patriotic envelopes. According to Steven R. Boyd in his book, Patriotic Envelopes of the Civil War: The Iconography of Union and Confederate Covers, “these prints encompassed an array of images, with the flags of the two nations among the most plentiful.” He explains that in the North, the Star-Spangled Banner became a symbol of the nation. He argues that by showcasing Old Glory patriotic envelopes, “symbolically deny the legality of the Southern states’ secession and the legitimacy of the Confederate government.”