The remembrance poppy was inspired by the World War I poem "In Flanders Fields" written by Canadian physician John McCrae on May 3, 1915 after witnessing the death of his friend, a fellow soldier. Its opening lines refer to the many poppies that were the first flowers to grow in the churned-up earth of soldiers' graves in Flanders, a region of Belgium. [This paragraph source: Widipedia]
Around the same time in the early 1920's, both the American Legion and the Royal British Legion started using the poppy as a symbol of honor and remembrance of the nearly 10 million soldiers who lost their lives in World War I. The poppy is traditionally worn on November 11th — Veterans Day in the Untited States, which is known as Remembrance Day in the United Kingdom and Commonwealth Nations.
November 11th is also called Armistice Day. On this day in 1918, WWI hostilities formally ended at the 11th hour, of the 11th day, of the 11th month, with the signing of an armistice by representatives of Germany and the Anglo-French Entente Cordiale.
In 1922, the Veterans of Foreign Wars adopted the poppy as the official memorial flower and began distributing poppies nationwide. From 1923 until this day the memorial poppies are made by disabled and needy American veterans. While making these poppies, the veterans often thought about their buddies who never came back from the war, and started calling the flowers "Buddy Poppy" in remembrance of their lost comrades.

The VFW now annually distributes free "Buddy"® Poppies around both the Memorial Day, and Veterans Day holidays. Any donations made go directly to programs in support of needy local veterans and family members of deceased veterans..
Wear your Buddy Poppy with pride!
Vestre Gravlund, Oslo, Norway
Photo by Natalie Maynor - Jackson, Mississippi, USA