States' first shots of World War I were fired from the castillo's battery in 1915. On March 21, 1915, Lt. Teofilo Marxuach was the officer of the day at El Morro Castle. The Odenwald, built in 1903 (not to be confused with the German World War II war ship which carried the same name), was an armed German supply ship which tried to force its way out of the bay and deliver supplies to the German submarines waiting in the Atlantic Ocean. Lt. Marxuach gave the order to open fire on the ship. The Odenwald was forced to return and its supplies were confiscated. The shots ordered by Lt. Marxuach have been considered as the first fired by the United States in World War I. The first actual wartime shot fired by the U.S. came on the day war was declared, during the Scuttling of SMS Cormoran off another small American island, Guam.
During World War II the United States Army added a massive concrete bunker to the top of El Morro to serve as a Harbor Defense Fire Control Station to direct a network of coastal artillery sites, and to keep watch for German submarines which were ravaging shipping in the Caribbean. A lighthouse, rebuilt by the U.S. Army in 1906�08 is the tallest point on El Morro, standing 180 feet (55 m) above sea level. Flagpoles on El Morro today customarily fly the United States flag, the Puerto Rican flag and the Cross of Burgundy Flag, also known in Spanish as las Aspas de Borgo�a, a standard which was widely used by Spanish armies around the world from 1506�1785.
National Park (1961�present)
In 1961, the United States Army officially retired from El Morro. The "fort" became a part of the National Park Service to be preserved as museums. In 1983, the Castillo and the city walls were declared a World Heritage Site by the United Nations. In honor of the Quincentennial of the voyages of Columbus in 1992 the exterior esplanade was cleared of palm trees that had been planted by the U.S. Army in the Fort Brooke era, and restored to the
