14 September 1814

Aboard the HMS Tonnant, at “dawn’s early light” attorney Francis Scott Key sees a large US flag still flying over Fort McHenry despite its overnight bombardment during the Battle of Baltimore in the War of 1812. He publishes his poem “Defence of Fort M’Henry” in the American and Commercial Daily Advertiser seven days later. Both the poem/lyrics and the Fort McHenry flag will later become known as the Star-Spangled Banner.
4 April 1818

The Third Flag Act (still in effect) returns the number of stripes to 13, and specifies: That on the admission of every new state into the Union, one star be added to the union of the flag; and that such addition shall take effect of the fourth day of July then next succeeding such admission.
1861-1865

The Civil War prompts, for the first time, widespread civilian adoption (in the Union states) of the flag. Prior to the war, the flag and its depiction were seldom seen apart from military and federal contexts.
7 June 1862

William Bruce Mumford becomes the only person to be executed for desecrating the US flag, after removing the flag Union soldiers had placed on the New Orleans mint and dragging it through the street. Occupying General Benjamin Butler vowed to punish him “in such a manner as… will caution both the perpetrators and abettors of the act, so that they will fear the stripes, if they do not reverence the stars of our banner”.
1872

George Henry Preble (1816 – 1885) publishes his Origin and History of the American Flag.
8 September 1892

Francis Bellamy publishes his Pledge of Allegiance in a children’s magazine, The Youth’s Companion, as part of a campaign to promote nationalism in and sell flags to public schools. It originally read: I pledge allegiance to my Flag and the Republic for which it stands, one nation, indivisible, with liberty and justice for all.
17 February 1897

The American Flag Association is organized to promote “the fostering of public sentiment in favor of honoring the flag of our country, and preserving it from desecration, and of initiating and forwarding legal measures to prevent such desecration”. Bellamy’s Pledge and the AFA are part of a larger flag protection movement that arose in the 1890s based in fears of immigrants as less than loyal or true Americans, and associated political dissent by “radicals” and “subversives”.