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 a German cargo liner trying to leave San Juan Bay without permission.

Marxuach ordered shots from a machine gun, and from a gun in the Santa Rosa battery of the Castillo San Felipe del Morro, in what are considered to be the first shots of World War I fired by the regular armed forces of the United States against any ship of the Central Powers,[1] forcing Odenwald to stop and to return to port.

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.

The Army Appropriation Bill created by an Act of Congress on March 2, 1889 authorized the creation of the first body of native troops in Puerto Rico.

On July 1, 1901, the United States Senate passed a bill that required a strict mental and physical examination for those who wanted to join the regiment.

34, War Department, July 29, 1904, the recruitment of native Puerto Rican civilians to be appointed the grade of second lieutenants for a term of four years was approved with the condition that they pass the required tests.

[6] Although many civilians from all walks of life applied for the officers appointment in January 1905, only seven made it that day, and one of those seven was Teófilo Marxuach, who had from 1903 to 1905 worked as a civil engineer for the Porto Rico regiment in the Aqueduct of Cayey.

He was assigned to the unit in charge of the Progressive Military Map of Puerto Rico from July 12, 1908 to December 4, 1908, during which time he was promoted to the rank of first lieutenant.

Sergeant Encarnacion Correa then manned a machine gun on the wall below "La Fortaleza", the Governor's residence, and fired warning shots at the ship with little effect.

[9] The first shots fired after the US Congress declared war on Germany on April 7, 1917 were by US Marines in Apra Harbor, Guam against a launch from SMS Cormoran.

On April 6, 1917, the US Congress declared war on Germany and on May 14, 1917, the Porto Rico Regiment was sent to Panama, where Marxuach served at the commanding post at Camp E.S.

[16] Congressional Gold Medal On June 10, 2014, President Barack Obama, signed the legislation known as "The Borinqueneers CGM Bill" at an official ceremony.