Get your custom Fox H-D one today. History of Challenge Coins: Challenge Coins surfaced during the World War 1 era. The practice of carrying a coin designed specifically for a unit was popular with the Army Special Forces. Carring the coin at all times and presenting it when "challenged" to prove affiliation with that unit resulted in a number of consequences for those who could not produce a coin; The most popular required the coinless soldier to buy a round of drinks. That practice continues to be popular today and one the Harley-Davidson riding community challenges regularly. Get your custom Fox H-D one today.