On June 20, 1782, the Continental Congress approved the design for the Great Seal of the United States, featuring a bald eagle grasping an olive branch and arrows and holding a scroll reading "E Pluribus Unum." Charles Thomson, who completed the design, explained that the eagle stands alone, "without any other supporters," to show that the United States "ought to rely on their own Virtue." The Great Seal is still used today to authenticate certain official U.S. documents.

Key wrote the poem after witnessing the British bombardment of Fort McHenry during the War of 1812, and it was soon set to an existing melody. For more than a century it was one of several patriotic songs played at official events, but it had no legal status. Congress finally designated it the official national anthem in a law signed on March 3, 1931.

Bellamy wrote the Pledge for The Youth's Companion, a popular family magazine that sponsored a nationwide school flag-raising ceremony in October 1892. Millions of American schoolchildren recited it that year. The wording has been revised several times since, most recently by Congress in 1954.

According to a popular account, Samuel Wilson, a meatpacker from Troy, New York, supplied barrels of beef to U.S. troops during the War of 1812 stamped "U.S." Soldiers reportedly joked the letters stood for their supplier, "Uncle Sam." Congress honored Wilson by name in 1961, though historians note the figure of Uncle Sam appears in references that may predate Wilson's involvement, and the exact origin remains debated.

In 1794, after Vermont and Kentucky joined the Union, Congress raised the flag to 15 stars and 15 stripes. Five more states then joined with no change to the flag, and adding a stripe for every new state was becoming impractical. Signed by President James Monroe on April 4, 1818, the Flag Act restored the flag to 13 stripes honoring the original states and specified that one star be added for each new state, effective the following Fourth of July — the rule still used today.