<iframe width="580" height="385" src="https://www.youtube.com/embed/su39ltkoyf0?hl=en" frameborder="0" allowfullscreen></iframe> <br>An Army veteran explains how the day got its start after World War I and evolved over the decades. <br><a href="https://www.youtube.com/watch?v=su39ltkoyf0">source</a>