Lieutenant Colonel Teófilo Marxuach, (July 28, 1877 – November 8, 1939), was the person who ordered the first shots fired in World War I on behalf of the United States on an armed German supply ship trying to force its way out of the San Juan Bay. Marxuach ordered hostile shots from a machine gun and a cannon located at the Santa Rosa battery of "El Morro" fort, in what is considered to be the first shots of World War I fired by the regular armed forces of the United States against any ship flying the colors of the Central Powers, forcing the Odenwald to stop and to return to port, where its supplies were confiscated. Early years Marxuach (birth name "Teófilo Marxuach Plumey") was born in the town of Arroyo, Puerto Rico when the island was still under Spanish rule. His parents were José María Marxuach, twice mayor of San Juan and Josefina Plumey Irizarry (daughter of Juan Bautista Plumey and Petronila Irizarry, among the wealthiest landholders in Lares). His family had historically played a prominent role in the island's commercial and political affairs. Marxuach and his three siblings Acisclo, Teresa (mother of Puerto Rican radio pioneer Teófilo Villavicencio) and Amalia were raised and educated in the capital city of San Juan. He studied military engineering at the Academy of Military Engineering in Guadalajara, Spain from September 1895 to July 1900 and graduated with a degree in civil engineering with a lieutenant's commission in the Spanish Army. When he returned to Puerto Rico in 1901, the island was a United States territory and no longer a Spanish province. Marxuach resigned his commission in the Spanish army and his Spanish citizenship. He then began to work as a civil engineer in the Department of Public Works. He enrolled in Cornell University and continued his engineering studies from 1902 to 1903. In 1903, Marxuach wrote and published "El lenguaje castellano en Puerto Rico" ("The Spanish Language in Puerto Rico"). In 1906, he married Carolina Acosta y Acosta (b. 1887), granddaughter of José Julián Acosta y Calvo in "La Capilla del Cristo" (Cristo Chapel) in Old San Juan. They had three children: Teófilo, Gilberto and Raúl Marxuach Acosta. Military career with the United States Puerto Rico became a U.S. Territory after the 1898 Treaty of Paris, which ended the Spanish–American War. The United States appointed a military governor, and the United States