The Battle of Grand Gulf was fought on April 29, 1863, during th: The UK was one of the Big Three powers (along with the US and the Soviet Union) who met to plan the post-war world;[99] it was an original signatory to the Declaration by United Nations and became one of the five permanent members of the United Nations Security Council. It worked closely with the United States to establish the IMF, World Bank and NATO.[100] The war left the UK severely weakened and financially dependent on the Marshall Plan,[101] but it was spared the total war that devastated eastern Europe.[102]