User:Hawkeye7/War/Selected anniversaries/May 21

May 21

 * 1863 - American Civil War: Siege of Port Hudson – Union forces begin to lay siege to the Confederate-controlled Port Hudson, Louisiana.
 * 1879 - War of the Pacific: Two Chilean ships blocking the harbor of Iquique, Chile, battle two Peruvian vessels in the Battle of Iquique.
 * 1941 - World War II: 950 miles off the coast of Brazil, the freighter SS Robin Moor becomes the first United States ship sunk by a German U-boat.
 * 1956 - Nuclear testing: In the Pacific Ocean, Bikini Atoll is nearly obliterated by the first airborne explosion of a hydrogen bomb.