Many historical events occurred on April 4th, and Russ Mitchell recaps them in this video clip from This Day In History. President William Henry Harrison became the first US President to die while in office when his cold turned into pneumonia. Congress passed and authorized what would become known as the American flag, with 13 strips, and then 20 stars with a blue background. Each state that would be added would add another star to the flag. Also, the first Mexican American, Henry Cisneros, became mayor of a major city, which was Texas. On Martin Luther King Jr.'s Memphis hotel balcony, James Earl Ray assassinated King.