The Green Beret, a recognized symbol of the U.S. Army Special Forces, has its roots in World War II. Although the U.S. Army Special Forces formally came into existence in 1952, their distinct headgear, influenced by European military styles, was adopted unofficially. It wasn’t until 1961 that President John F. Kennedy sanctioned its official use, emphasizing its significance in the Army.
  

Key Points: 

1. The U.S. Army Special Forces’ lineage is traced back to the First Special Service Force of 1942, a joint U.S.-Canadian unit formed for unconventional warfare in Nazi-occupied Norway.
2. The green beret’s origin dates back to WWII, influenced by European headwear, particularly the berets favored by French, Belgian, and British Commando troops.
3. Despite the Army’s initial reluctance, the green beret was informally adopted by the Special Forces in 1953 and was widely used during field exercises.
4. President John F. Kennedy officially endorsed the use of the Green Beret in 1961, asserting that the Special Forces required a unique identifier for their distinctive mission.
5. Following Kennedy’s assassination, the Green Berets held the honored position of serving as the Honor Guard during his funeral procession.

Source: https://www.militarytimes.com/off-duty/military-culture/2023/10/10/how-the-green-beret-became-the-symbol-of-us-army-special-forces/