On this day in 1777 the Continental Congress adopts the "stars and stripes" as the flag of the infantile nation. Many different flags were proposed, but the flag with the 13 stripes (they're for luck if you ask Homer Simpson) and the 13 stars in a circular pattern was the winner.
On this day in 1903 Heppner, Oregon was wiped off the map as the result of a flash flood. The tiny central Oregon town was built on a flood plain and a strong late spring thunderstorm in the mountains that surrounded the town caused a twenty-foot tall wall of water to envelope the citizens and wash them away. 324 people were killed.
On this day in 1924 Warren G. Harding became to first president to be heard on the radio. He was dedicating a memorial to Francis Scott Key and the "Star Spangled Banner".
On this day in 1846 the Bear Flag revolt began. It was an anticipatory move by settlers in California against the Mexican government. They declared the short lived California Republic independent from Mexico and sided with the US when war broke out with Mexico. The rabble was started by John C. Fremont, the explorer sent west by the US government to map the west for further expansion. He drummed up support for a revolt in Sonoma, California that turned out to be a bloodless battle. But significant in it was the first skirmish of the Mexican-American war.