The holiday that became Veterans Day was first observed as Armistice Day, and it didn’t become an official national holiday in the United States until 1938. Then in 1954 it was renamed Veterans Day to honor those who had served in all U.S. wars.

In Britain the second Sunday of November is observed as Remembrance Sunday, and in Canada it is observed as Remembrance Day. The occasion is marked by the red poppy, a flower that came to symbolize remembrance, as popularized in John McCrae’s poem “In Flanders Fields.” And while Remembrance Day is observed in Australia and New Zealand, the holiday marking the landing of ANZAC troops during the Gallipoli Campaign—known as ANZAC Day—looms larger in the public consciousness as a World War I-related observance.

In 1920, an unknown soldier was interred at Westminster Abbey in London, and the same tribute was held in Paris the next year at the Arc de Triomphe. In 1921 Armistice Day was commemorated in the United States with the burial of an unknown soldier from World War I at Arlington National Cemetery in Arlington, Virginia. Ceremonies are held each year at the Tomb of the Unknowns, and floral tributes are placed on the graves of service members and at memorials throughout the country.